NCBI Home Page NCBI Site Search page NCBI Guide that lists and describes the NCBI resources
Conserved domains on  [gi|1675114744|ref|WP_138627366|]
View 

acyl-CoA desaturase [Pseudoalteromonas sp. S4741]

Protein Classification

fatty acid desaturase family protein( domain architecture ID 11461513)

fatty acid desaturase family protein may remove two hydrogen atoms from a fatty acid, creating a carbon/carbon double bond; such as Mycobacterium tuberculosis NADPH-dependent stearoyl-CoA 9-desaturase

EC:  1.14.19.-
PubMed:  15189125

Graphical summary

 Zoom to residue level

show extra options »

Show site features     Horizontal zoom: ×

List of domain hits

Name Accession Description Interval E-value
DesA COG3239
Fatty acid desaturase [Lipid transport and metabolism];
1-350 2.22e-54

Fatty acid desaturase [Lipid transport and metabolism];


:

Pssm-ID: 442471 [Multi-domain]  Cd Length: 319  Bit Score: 181.08  E-value: 2.22e-54
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744   1 MTTINYQQLAE--DLDGIKMSTLAKVGQKDANYIRSIVRKQRLCeIGGRILLMLGFVQPLLWVagvlLLALAKILDNMeI 78
Cdd:COG3239     1 MTTATPLTPADeaELRALRARLRALLGRRDWRYLLKLALTLALL-AALWLLLSWSWLALLAAL----LLGLALAGLFS-L 74
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  79 GHNVMHGQYDWMN-DKQLNSKTYEWDIACDGQSWNRVHNfEHHTYTNIIGKDRDFGYGLLRLSndfKWRLKNTWqFITYL 157
Cdd:COG3239    75 GHDAGHGSLFRSRwLNDLLGRLLGLPLGTPYDAWRRSHN-RHHAYTNDPGKDPDIGYGVQAWR---PLYLFQHL-LRFFL 149
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 158 NLSVLFQWGVSYHELAGERVFIGKKKPNRKGAvahstlkkrFFSKGARQLIkDYVLFPllagplFLWVLSGNLLANLIRN 237
Cdd:COG3239   150 LGLGGLYWLLALDFLPLRGRLELKERRLEALL---------LLLFLAALLA-LLLALG------WWAVLLFWLLPLLVAG 213
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 238 LWTSTIIFCGHFTEQTHtfyeqdcenesqGQWYYRQALGSSNIKGARWFHILTGHLSFQIEHHLFPDMPSSRYQEIAPQV 317
Cdd:COG3239   214 LLLGLRFYLEHRGEDTG------------DGEYRDQLLGSRNIRGGRLLRWLFGNLNYHIEHHLFPSIPWYRLPEAHRIL 281
                         330       340       350
                  ....*....|....*....|....*....|...
gi 1675114744 318 QAALQKQGIAYNTGGFFHQYTSVLKRIFRYSFK 350
Cdd:COG3239   282 KELCPEYGLPYTEGSLLRSYREVLRLLRRLGLP 314
 
Name Accession Description Interval E-value
DesA COG3239
Fatty acid desaturase [Lipid transport and metabolism];
1-350 2.22e-54

Fatty acid desaturase [Lipid transport and metabolism];


Pssm-ID: 442471 [Multi-domain]  Cd Length: 319  Bit Score: 181.08  E-value: 2.22e-54
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744   1 MTTINYQQLAE--DLDGIKMSTLAKVGQKDANYIRSIVRKQRLCeIGGRILLMLGFVQPLLWVagvlLLALAKILDNMeI 78
Cdd:COG3239     1 MTTATPLTPADeaELRALRARLRALLGRRDWRYLLKLALTLALL-AALWLLLSWSWLALLAAL----LLGLALAGLFS-L 74
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  79 GHNVMHGQYDWMN-DKQLNSKTYEWDIACDGQSWNRVHNfEHHTYTNIIGKDRDFGYGLLRLSndfKWRLKNTWqFITYL 157
Cdd:COG3239    75 GHDAGHGSLFRSRwLNDLLGRLLGLPLGTPYDAWRRSHN-RHHAYTNDPGKDPDIGYGVQAWR---PLYLFQHL-LRFFL 149
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 158 NLSVLFQWGVSYHELAGERVFIGKKKPNRKGAvahstlkkrFFSKGARQLIkDYVLFPllagplFLWVLSGNLLANLIRN 237
Cdd:COG3239   150 LGLGGLYWLLALDFLPLRGRLELKERRLEALL---------LLLFLAALLA-LLLALG------WWAVLLFWLLPLLVAG 213
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 238 LWTSTIIFCGHFTEQTHtfyeqdcenesqGQWYYRQALGSSNIKGARWFHILTGHLSFQIEHHLFPDMPSSRYQEIAPQV 317
Cdd:COG3239   214 LLLGLRFYLEHRGEDTG------------DGEYRDQLLGSRNIRGGRLLRWLFGNLNYHIEHHLFPSIPWYRLPEAHRIL 281
                         330       340       350
                  ....*....|....*....|....*....|...
gi 1675114744 318 QAALQKQGIAYNTGGFFHQYTSVLKRIFRYSFK 350
Cdd:COG3239   282 KELCPEYGLPYTEGSLLRSYREVLRLLRRLGLP 314
Delta6-FADS-like cd03506
The Delta6 Fatty Acid Desaturase (Delta6-FADS)-like CD includes the integral-membrane enzymes: ...
61-326 4.96e-49

The Delta6 Fatty Acid Desaturase (Delta6-FADS)-like CD includes the integral-membrane enzymes: delta-4, delta-5, delta-6, delta-8, delta-8-sphingolipid, and delta-11 desaturases found in vertebrates, higher plants, fungi, and bacteria. These desaturases are required for the synthesis of highly unsaturated fatty acids (HUFAs), which are mainly esterified into phospholipids and contribute to maintaining membrane fluidity. While HUFAs may be required for cold tolerance in bacteria, plants and fish, the primary role of HUFAs in mammals is cell signaling. These enzymes are described as front-end desaturases because they introduce a double bond between the pre-exiting double bond and the carboxyl (front) end of the fatty acid. Various substrates are involved, with both acyl-coenzyme A (CoA) and acyl-lipid desaturases present in this CD. Acyl-lipid desaturases are localized in the membranes of cyanobacterial thylakoid, plant endoplasmic reticulum (ER), and plastid; and acyl-CoA desaturases are present in ER membrane. ER-bound plant acyl-lipid desaturases and acyl-CoA desaturases require cytochrome b5 as an electron donor. Most of the eukaryotic desaturase domains have an adjacent N-terminal cytochrome b5-like domain. This domain family has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of sequences also reveals the existence of three regions of conserved histidine cluster motifs that contain the residues: HXXXH, HXX(X)HH, and Q/HXXHH. These histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the homolog, stearoyl CoA desaturase.


Pssm-ID: 239583 [Multi-domain]  Cd Length: 204  Bit Score: 163.58  E-value: 4.96e-49
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  61 VAGVLLLALAKILdNMEIGHNVMHGQYD-WMNDKQLNSKTYEWDIACDGQSWNRVHNFeHHTYTNIIGKDRDFGYGLLRL 139
Cdd:cd03506     1 LLLAILLGLFWAQ-GGFLAHDAGHGQVFkNRWLNKLLGLTVGNLLGASAGWWKNKHNV-HHAYTNILGHDPDIDTLPLLA 78
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 140 SNDFKWRLKNTWQFItylnlsVLFQWgvsyhelagervfigkkkpnrkgavahstlkkrffskgarqlikdyvlfpLLAG 219
Cdd:cd03506    79 RSEPAFGKDQKKRFL------HRYQH--------------------------------------------------FYFF 102
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 220 PLFLWVLSGNLLANLIRNLWTSTIIFCGHFTEQTHTFyeqdcENESQGQWYYRQALGSSNIKGARWFHILTGHLSFQIEH 299
Cdd:cd03506   103 PLLALLLLAFLVVQLAGGLWLAVVFQLNHFGMPVEDP-----PGESKNDWLERQVLTTRNITGSPFLDWLHGGLNYQIEH 177
                         250       260
                  ....*....|....*....|....*..
gi 1675114744 300 HLFPDMPSSRYQEIAPQVQAALQKQGI 326
Cdd:cd03506   178 HLFPTMPRHNYPKVAPLVRELCKKHGL 204
FA_desaturase pfam00487
Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a ...
61-332 2.69e-14

Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a double bond at the delta position of fatty acids. There seem to be two distinct families of fatty acid desaturases which do not seem to be evolutionary related: Family 1 composed of Stearoyl-CoA desaturases (SCD) and Family 2 composed of Bacterial fatty acid desaturases, Plant stearoyl-acyl-carrier-protein desaturase and Cyanobacterial DesA. Members of this entry are ER integral membrane proteins that share the same mushroom-shaped fold consisting of four transmembrane helices (TM1-TM4) which anchor them to the membrane, capped by a cytosolic domain containing a unique 9-10 histidine- coordinating di metal (di-iron) catalytic centre. The structure of mouse stearoyl-CoA desaturase (SDC) revealed that TM2 and TM4 are longer than TM1 and TM3 and protrude into the cytosolic domain, providing three of the nine histidine residues that coordinate the two metal ions, while the other histidine residues are provided by the soluble domain in this enzyme.


Pssm-ID: 425713 [Multi-domain]  Cd Length: 252  Bit Score: 71.61  E-value: 2.69e-14
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  61 VAGVLLLALAKILDNMEIGHNVMHGQ-------YDWMNDkqLNSKTYEWDIACDGQSWNRVHNfEHHTYTNIIGKDRDFG 133
Cdd:pfam00487   5 LLLALLLGLFLLGITGSLAHEASHGAlfkkrrlNRWLND--LLGRLAGLPLGISYSAWRIAHL-VHHRYTNGPDKDPDTA 81
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 134 YGLLRLSNDFKWRLKntwqfitYLNLSVLFQWGVSYHELAGERVFIGKKKPnrkgavahstlkkRFFSKGARQLIKDYVL 213
Cdd:pfam00487  82 PLASRFRGLLRYLLR-------WLLGLLVLAWLLALVLPLWLRRLARRKRP-------------IKSRRRRWRLIAWLLL 141
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 214 FPLLAGPLFLWVLSGNLLANLirnlWTSTIIFCGHFTEQTHTFYEqdcenESQGQWYYRQALGSSNIKGARWF-HILTGH 292
Cdd:pfam00487 142 LAAWLGLWLGFLGLGGLLLLL----WLLPLLVFGFLLALIFNYLE-----HYGGDWGERPVETTRSIRSPNWWlNLLTGN 212
                         250       260       270       280
                  ....*....|....*....|....*....|....*....|
gi 1675114744 293 LSFQIEHHLFPDMPSSRYQEIAPQVQAALQKQGIAYNTGG 332
Cdd:pfam00487 213 LNYHIEHHLFPGVPWYRLPKLHRRLREALPEHGLPYRSLG 252
PLN03198 PLN03198
delta6-acyl-lipid desaturase; Provisional
273-328 3.77e-08

delta6-acyl-lipid desaturase; Provisional


Pssm-ID: 178739 [Multi-domain]  Cd Length: 526  Bit Score: 54.70  E-value: 3.77e-08
                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1675114744 273 QALGSSNIKGARWFHILTGHLSFQIEHHLFPDMPSSRYQEIAPQVQAALQKQGIAY 328
Cdd:PLN03198  440 QIVSTRDIKANIFNDWFTGGLNRQIEHHLFPTMPRHNLNKIAPQVEAFCIKHGLVY 495
 
Name Accession Description Interval E-value
DesA COG3239
Fatty acid desaturase [Lipid transport and metabolism];
1-350 2.22e-54

Fatty acid desaturase [Lipid transport and metabolism];


Pssm-ID: 442471 [Multi-domain]  Cd Length: 319  Bit Score: 181.08  E-value: 2.22e-54
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744   1 MTTINYQQLAE--DLDGIKMSTLAKVGQKDANYIRSIVRKQRLCeIGGRILLMLGFVQPLLWVagvlLLALAKILDNMeI 78
Cdd:COG3239     1 MTTATPLTPADeaELRALRARLRALLGRRDWRYLLKLALTLALL-AALWLLLSWSWLALLAAL----LLGLALAGLFS-L 74
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  79 GHNVMHGQYDWMN-DKQLNSKTYEWDIACDGQSWNRVHNfEHHTYTNIIGKDRDFGYGLLRLSndfKWRLKNTWqFITYL 157
Cdd:COG3239    75 GHDAGHGSLFRSRwLNDLLGRLLGLPLGTPYDAWRRSHN-RHHAYTNDPGKDPDIGYGVQAWR---PLYLFQHL-LRFFL 149
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 158 NLSVLFQWGVSYHELAGERVFIGKKKPNRKGAvahstlkkrFFSKGARQLIkDYVLFPllagplFLWVLSGNLLANLIRN 237
Cdd:COG3239   150 LGLGGLYWLLALDFLPLRGRLELKERRLEALL---------LLLFLAALLA-LLLALG------WWAVLLFWLLPLLVAG 213
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 238 LWTSTIIFCGHFTEQTHtfyeqdcenesqGQWYYRQALGSSNIKGARWFHILTGHLSFQIEHHLFPDMPSSRYQEIAPQV 317
Cdd:COG3239   214 LLLGLRFYLEHRGEDTG------------DGEYRDQLLGSRNIRGGRLLRWLFGNLNYHIEHHLFPSIPWYRLPEAHRIL 281
                         330       340       350
                  ....*....|....*....|....*....|...
gi 1675114744 318 QAALQKQGIAYNTGGFFHQYTSVLKRIFRYSFK 350
Cdd:COG3239   282 KELCPEYGLPYTEGSLLRSYREVLRLLRRLGLP 314
Delta6-FADS-like cd03506
The Delta6 Fatty Acid Desaturase (Delta6-FADS)-like CD includes the integral-membrane enzymes: ...
61-326 4.96e-49

The Delta6 Fatty Acid Desaturase (Delta6-FADS)-like CD includes the integral-membrane enzymes: delta-4, delta-5, delta-6, delta-8, delta-8-sphingolipid, and delta-11 desaturases found in vertebrates, higher plants, fungi, and bacteria. These desaturases are required for the synthesis of highly unsaturated fatty acids (HUFAs), which are mainly esterified into phospholipids and contribute to maintaining membrane fluidity. While HUFAs may be required for cold tolerance in bacteria, plants and fish, the primary role of HUFAs in mammals is cell signaling. These enzymes are described as front-end desaturases because they introduce a double bond between the pre-exiting double bond and the carboxyl (front) end of the fatty acid. Various substrates are involved, with both acyl-coenzyme A (CoA) and acyl-lipid desaturases present in this CD. Acyl-lipid desaturases are localized in the membranes of cyanobacterial thylakoid, plant endoplasmic reticulum (ER), and plastid; and acyl-CoA desaturases are present in ER membrane. ER-bound plant acyl-lipid desaturases and acyl-CoA desaturases require cytochrome b5 as an electron donor. Most of the eukaryotic desaturase domains have an adjacent N-terminal cytochrome b5-like domain. This domain family has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of sequences also reveals the existence of three regions of conserved histidine cluster motifs that contain the residues: HXXXH, HXX(X)HH, and Q/HXXHH. These histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the homolog, stearoyl CoA desaturase.


Pssm-ID: 239583 [Multi-domain]  Cd Length: 204  Bit Score: 163.58  E-value: 4.96e-49
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  61 VAGVLLLALAKILdNMEIGHNVMHGQYD-WMNDKQLNSKTYEWDIACDGQSWNRVHNFeHHTYTNIIGKDRDFGYGLLRL 139
Cdd:cd03506     1 LLLAILLGLFWAQ-GGFLAHDAGHGQVFkNRWLNKLLGLTVGNLLGASAGWWKNKHNV-HHAYTNILGHDPDIDTLPLLA 78
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 140 SNDFKWRLKNTWQFItylnlsVLFQWgvsyhelagervfigkkkpnrkgavahstlkkrffskgarqlikdyvlfpLLAG 219
Cdd:cd03506    79 RSEPAFGKDQKKRFL------HRYQH--------------------------------------------------FYFF 102
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 220 PLFLWVLSGNLLANLIRNLWTSTIIFCGHFTEQTHTFyeqdcENESQGQWYYRQALGSSNIKGARWFHILTGHLSFQIEH 299
Cdd:cd03506   103 PLLALLLLAFLVVQLAGGLWLAVVFQLNHFGMPVEDP-----PGESKNDWLERQVLTTRNITGSPFLDWLHGGLNYQIEH 177
                         250       260
                  ....*....|....*....|....*..
gi 1675114744 300 HLFPDMPSSRYQEIAPQVQAALQKQGI 326
Cdd:cd03506   178 HLFPTMPRHNYPKVAPLVRELCKKHGL 204
FA_desaturase pfam00487
Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a ...
61-332 2.69e-14

Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a double bond at the delta position of fatty acids. There seem to be two distinct families of fatty acid desaturases which do not seem to be evolutionary related: Family 1 composed of Stearoyl-CoA desaturases (SCD) and Family 2 composed of Bacterial fatty acid desaturases, Plant stearoyl-acyl-carrier-protein desaturase and Cyanobacterial DesA. Members of this entry are ER integral membrane proteins that share the same mushroom-shaped fold consisting of four transmembrane helices (TM1-TM4) which anchor them to the membrane, capped by a cytosolic domain containing a unique 9-10 histidine- coordinating di metal (di-iron) catalytic centre. The structure of mouse stearoyl-CoA desaturase (SDC) revealed that TM2 and TM4 are longer than TM1 and TM3 and protrude into the cytosolic domain, providing three of the nine histidine residues that coordinate the two metal ions, while the other histidine residues are provided by the soluble domain in this enzyme.


Pssm-ID: 425713 [Multi-domain]  Cd Length: 252  Bit Score: 71.61  E-value: 2.69e-14
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  61 VAGVLLLALAKILDNMEIGHNVMHGQ-------YDWMNDkqLNSKTYEWDIACDGQSWNRVHNfEHHTYTNIIGKDRDFG 133
Cdd:pfam00487   5 LLLALLLGLFLLGITGSLAHEASHGAlfkkrrlNRWLND--LLGRLAGLPLGISYSAWRIAHL-VHHRYTNGPDKDPDTA 81
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 134 YGLLRLSNDFKWRLKntwqfitYLNLSVLFQWGVSYHELAGERVFIGKKKPnrkgavahstlkkRFFSKGARQLIKDYVL 213
Cdd:pfam00487  82 PLASRFRGLLRYLLR-------WLLGLLVLAWLLALVLPLWLRRLARRKRP-------------IKSRRRRWRLIAWLLL 141
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 214 FPLLAGPLFLWVLSGNLLANLirnlWTSTIIFCGHFTEQTHTFYEqdcenESQGQWYYRQALGSSNIKGARWF-HILTGH 292
Cdd:pfam00487 142 LAAWLGLWLGFLGLGGLLLLL----WLLPLLVFGFLLALIFNYLE-----HYGGDWGERPVETTRSIRSPNWWlNLLTGN 212
                         250       260       270       280
                  ....*....|....*....|....*....|....*....|
gi 1675114744 293 LSFQIEHHLFPDMPSSRYQEIAPQVQAALQKQGIAYNTGG 332
Cdd:pfam00487 213 LNYHIEHHLFPGVPWYRLPKLHRRLREALPEHGLPYRSLG 252
PLN03198 PLN03198
delta6-acyl-lipid desaturase; Provisional
273-328 3.77e-08

delta6-acyl-lipid desaturase; Provisional


Pssm-ID: 178739 [Multi-domain]  Cd Length: 526  Bit Score: 54.70  E-value: 3.77e-08
                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1675114744 273 QALGSSNIKGARWFHILTGHLSFQIEHHLFPDMPSSRYQEIAPQVQAALQKQGIAY 328
Cdd:PLN03198  440 QIVSTRDIKANIFNDWFTGGLNRQIEHHLFPTMPRHNLNKIAPQVEAFCIKHGLVY 495
Delta12-FADS-like cd03507
The Delta12 Fatty Acid Desaturase (Delta12-FADS)-like CD includes the integral-membrane ...
211-307 9.20e-05

The Delta12 Fatty Acid Desaturase (Delta12-FADS)-like CD includes the integral-membrane enzymes, delta-12 acyl-lipid desaturases, oleate 12-hydroxylases, omega3 and omega6 fatty acid desaturases, and other related proteins, found in a wide range of organisms including higher plants, green algae, diatoms, nematodes, fungi, and bacteria. The expression of these proteins appears to be temperature dependent: decreases in temperature result in increased levels of fatty acid desaturation within membrane lipids subsequently altering cell membrane fluidity. An important enzyme for the production of polyunsaturates in plants is the oleate delta-12 desaturase (Arabidopsis FAD2) of the endoplasmic reticulum. This enzyme accepts l-acyl-2-oleoyl-sn-glycero-3-phosphocholine as substrate and requires NADH:cytochrome b oxidoreductase, cytochrome b, and oxygen for activity. FAD2 converts oleate(18:1) to linoleate (18:2) and is closely related to oleate 12-hydroxylase which catalyzes the hydroxylation of oleate to ricinoleate. Plastid-bound desaturases (Arabidopsis delta-12 desaturase (FAD6), omega-3 desaturase (FAD8), omega-6 desaturase (FAD6)), as well as, the cyanobacterial thylakoid-bound FADSs require oxygen, ferredoxin, and ferredoxin oxidoreductase for activity. As in higher plants, the cyanobacteria delta-12 (DesA) and omega-3 (DesB) FADSs desaturate oleate (18:1) to linoleate (18:2) and linoleate (18:2) to linolenate (18:3), respectively. Omega-3 (DesB/FAD8) and omega-6 (DesD/FAD6) desaturases catalyze reactions that introduce a double bond between carbons three and four, and carbons six and seven, respectively, from the methyl end of fatty acids. As with other members of this superfamily, this domain family has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of sequences also reveals the existence of three regions of conserved histidine cluster motifs that contain eight histidine residues: HXXXH, HXX(X)HH, and HXXHH. These histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the homologue, stearoyl CoA desaturase. Mutation of any one of four of these histidines in the Synechocystis delta-12 acyl-lipid desaturase resulted in complete inactivity.


Pssm-ID: 239584 [Multi-domain]  Cd Length: 222  Bit Score: 42.98  E-value: 9.20e-05
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744 211 YVLFPLLAGPLFLWVLSGNLLANLIRNLWTSTIIFCGHFTEQTHtFYEQDCENesqgqWYYRQALGSSNIKGARWFHILT 290
Cdd:cd03507   129 LMLSLGWPYYLLLNVLLYYLIPYLVVNAWLVLITYLQHTFPDIP-WYRADEWN-----FAQAGLLGTVDRDYGGWLNWLT 202
                          90
                  ....*....|....*..
gi 1675114744 291 GHLSFQIEHHLFPDMPS 307
Cdd:cd03507   203 HIIGTHVAHHLFPRIPH 219
Membrane-FADS-like cd01060
The membrane fatty acid desaturase (Membrane_FADS)-like CD includes membrane FADSs, alkane ...
61-170 2.87e-04

The membrane fatty acid desaturase (Membrane_FADS)-like CD includes membrane FADSs, alkane hydroxylases, beta carotene ketolases (CrtW-like), hydroxylases (CrtR-like), and other related proteins. They are present in all groups of organisms with the exception of archaea. Membrane FADSs are non-heme, iron-containing, oxygen-dependent enzymes involved in regioselective introduction of double bonds in fatty acyl aliphatic chains. They play an important role in the maintenance of the proper structure and functioning of biological membranes. Alkane hydroxylases are bacterial, integral-membrane di-iron enzymes that share a requirement for iron and oxygen for activity similar to that of membrane FADSs, and are involved in the initial oxidation of inactivated alkanes. Beta-carotene ketolase and beta-carotene hydroxylase are carotenoid biosynthetic enzymes for astaxanthin and zeaxanthin, respectively. This superfamily domain has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of these sequences also reveals three regions of conserved histidine cluster motifs that contain eight histidine residues: HXXX(X)H, HXX(X)HH, and HXXHH (an additional conserved histidine residue is seen between clusters 2 and 3). Spectroscopic and genetic evidence point to a nitrogen-rich coordination environment located in the cytoplasm with as many as eight histidines coordinating the two iron ions and a carboxylate residue bridging the two metals in the Pseudomonas oleovorans alkane hydroxylase (AlkB). In addition, the eight histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the rat stearoyl CoA delta-9 desaturase.


Pssm-ID: 238511 [Multi-domain]  Cd Length: 122  Bit Score: 40.15  E-value: 2.87e-04
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1675114744  61 VAGVLLLALAKILDNMEIGHNVMHGQYD---WMNDkqLNSKTYEWDIACDGQSWNRVHNfEHHTYTNIIGKDRDFGYGLL 137
Cdd:cd01060     1 LLLALLLGLLGGLGLTVLAHELGHRSFFrsrWLNR--LLGALLGLALGGSYGWWRRSHR-RHHRYTNTPGKDPDSAVNYL 77
                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 1675114744 138 -----RLSNDFKWRLKNTWQFITYLNLSVLFQWGVSYH 170
Cdd:cd01060    78 ehyggDRPFDTDGEWLRTTDNSRNGWLNLLLTGGLGYH 115
Membrane-FADS-like cd01060
The membrane fatty acid desaturase (Membrane_FADS)-like CD includes membrane FADSs, alkane ...
272-303 3.13e-03

The membrane fatty acid desaturase (Membrane_FADS)-like CD includes membrane FADSs, alkane hydroxylases, beta carotene ketolases (CrtW-like), hydroxylases (CrtR-like), and other related proteins. They are present in all groups of organisms with the exception of archaea. Membrane FADSs are non-heme, iron-containing, oxygen-dependent enzymes involved in regioselective introduction of double bonds in fatty acyl aliphatic chains. They play an important role in the maintenance of the proper structure and functioning of biological membranes. Alkane hydroxylases are bacterial, integral-membrane di-iron enzymes that share a requirement for iron and oxygen for activity similar to that of membrane FADSs, and are involved in the initial oxidation of inactivated alkanes. Beta-carotene ketolase and beta-carotene hydroxylase are carotenoid biosynthetic enzymes for astaxanthin and zeaxanthin, respectively. This superfamily domain has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of these sequences also reveals three regions of conserved histidine cluster motifs that contain eight histidine residues: HXXX(X)H, HXX(X)HH, and HXXHH (an additional conserved histidine residue is seen between clusters 2 and 3). Spectroscopic and genetic evidence point to a nitrogen-rich coordination environment located in the cytoplasm with as many as eight histidines coordinating the two iron ions and a carboxylate residue bridging the two metals in the Pseudomonas oleovorans alkane hydroxylase (AlkB). In addition, the eight histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the rat stearoyl CoA delta-9 desaturase.


Pssm-ID: 238511 [Multi-domain]  Cd Length: 122  Bit Score: 37.06  E-value: 3.13e-03
                          10        20        30
                  ....*....|....*....|....*....|..
gi 1675114744 272 RQALGSSNIKGARWFHILTGHLSFQIEHHLFP 303
Cdd:cd01060    91 EWLRTTDNSRNGWLNLLLTGGLGYHNEHHLFP 122
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
Help | Disclaimer | Write to the Help Desk
NCBI | NLM | NIH