NCBI Home Page NCBI Site Search page NCBI Guide that lists and describes the NCBI resources
Conserved domains on  [gi|655375068|ref|WP_028780502|]
View 

MULTISPECIES: porin [Shewanella]

Protein Classification

porin( domain architecture ID 10007050)

porin forms an aqueous channel for the diffusion of small hydrophilic molecules across the outer membrane

CATH:  2.40.160.10
Gene Ontology:  GO:0009279|GO:0016020|GO:0015288
PubMed:  31214985|31792365
SCOP:  4003061
TCDB:  1.B.1

Graphical summary

 Zoom to residue level

show extra options »

Show site features     Horizontal zoom: ×

List of domain hits

Name Accession Description Interval E-value
OmpC COG3203
Outer membrane porin OmpC/OmpF/PhoE [Cell wall/membrane/envelope biogenesis];
4-352 1.10e-36

Outer membrane porin OmpC/OmpF/PhoE [Cell wall/membrane/envelope biogenesis];


:

Pssm-ID: 442436 [Multi-domain]  Cd Length: 336  Bit Score: 135.13  E-value: 1.10e-36
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   4 TLISASVATVLAAASFGAlaDGPTLYGRLDLSITNSD-QGATLQTGTNGVevgesgtyieNNFSHLGVKGSEKISDGVDI 82
Cdd:COG3203    1 TLLALAVAAALAGAAHAQ--SSVTLYGRVDAGVEYVDnGGGSLTRLTSGG----------DSGSRLGFKGSEDLGGGLKA 68
                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  83 IYQMEFQVEN---TSGSGDTFKARNTYLGAK-TNFGTVLAGRNDTVFKQAEGGVDVFGNT----NADIDRMLGGQVRSGD 154
Cdd:COG3203   69 IFQLESGFNAdtgTSGGGGRLFGRQAYVGLKgDDFGTLTLGRQYTPLYDVVGAFDPFGDSgdagNLAGDDNLAGTGRADN 148
                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 155 GVWYYSPKIADLiTLNATYLMEDNYATYDANgneidkdNMYALSATigdkkLKAQNYYAAIAYNKAIGG---------ID 225
Cdd:COG3203  149 AIKYRSPNFGGL-TFGAQYSFGEDAGSSSNG-------RGYGAGLT-----YANGPLSLGAAYQQSNDAqgataggddAD 215
                        250       260       270       280       290       300       310       320
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 226 AYRAVGQVKLGDFKLGGLFQNSESIVDGSDDN---NTYFVNVVYNLNG-VNLKLQYGYDEagfgkyykalGDNAGTDIEV 301
Cdd:COG3203  216 AWGLGASYDFGNLKLAAGYGQTKNDDAGGAGNakaDGYELGASYPFGPaLTLSASYGYTD----------AKDGADDDDA 285
                        330       340       350       360       370
                 ....*....|....*....|....*....|....*....|....*....|.
gi 655375068 302 TNITVGADYRVAKSTLLFAHYANYQGEYKDAGAKFDLEDDNVFTVGVRYDF 352
Cdd:COG3203  286 NQYALGADYALSKRTSLYAEYGYNDNDGNANFTAAAGDTDDGVAVGLRHKF 336
 
Name Accession Description Interval E-value
OmpC COG3203
Outer membrane porin OmpC/OmpF/PhoE [Cell wall/membrane/envelope biogenesis];
4-352 1.10e-36

Outer membrane porin OmpC/OmpF/PhoE [Cell wall/membrane/envelope biogenesis];


Pssm-ID: 442436 [Multi-domain]  Cd Length: 336  Bit Score: 135.13  E-value: 1.10e-36
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   4 TLISASVATVLAAASFGAlaDGPTLYGRLDLSITNSD-QGATLQTGTNGVevgesgtyieNNFSHLGVKGSEKISDGVDI 82
Cdd:COG3203    1 TLLALAVAAALAGAAHAQ--SSVTLYGRVDAGVEYVDnGGGSLTRLTSGG----------DSGSRLGFKGSEDLGGGLKA 68
                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  83 IYQMEFQVEN---TSGSGDTFKARNTYLGAK-TNFGTVLAGRNDTVFKQAEGGVDVFGNT----NADIDRMLGGQVRSGD 154
Cdd:COG3203   69 IFQLESGFNAdtgTSGGGGRLFGRQAYVGLKgDDFGTLTLGRQYTPLYDVVGAFDPFGDSgdagNLAGDDNLAGTGRADN 148
                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 155 GVWYYSPKIADLiTLNATYLMEDNYATYDANgneidkdNMYALSATigdkkLKAQNYYAAIAYNKAIGG---------ID 225
Cdd:COG3203  149 AIKYRSPNFGGL-TFGAQYSFGEDAGSSSNG-------RGYGAGLT-----YANGPLSLGAAYQQSNDAqgataggddAD 215
                        250       260       270       280       290       300       310       320
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 226 AYRAVGQVKLGDFKLGGLFQNSESIVDGSDDN---NTYFVNVVYNLNG-VNLKLQYGYDEagfgkyykalGDNAGTDIEV 301
Cdd:COG3203  216 AWGLGASYDFGNLKLAAGYGQTKNDDAGGAGNakaDGYELGASYPFGPaLTLSASYGYTD----------AKDGADDDDA 285
                        330       340       350       360       370
                 ....*....|....*....|....*....|....*....|....*....|.
gi 655375068 302 TNITVGADYRVAKSTLLFAHYANYQGEYKDAGAKFDLEDDNVFTVGVRYDF 352
Cdd:COG3203  286 NQYALGADYALSKRTSLYAEYGYNDNDGNANFTAAAGDTDDGVAVGLRHKF 336
Porin_4 pfam13609
Gram-negative porin;
11-328 3.04e-32

Gram-negative porin;


Pssm-ID: 433346 [Multi-domain]  Cd Length: 311  Bit Score: 122.55  E-value: 3.04e-32
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   11 ATVLAAASFGALAD-GPTLYGRLDLSITNSDQGATLQTGTNGVEVgesgtyieNNFSHLGVKGSEKISDGVDiiYQMEFQ 89
Cdd:pfam13609   2 LAALAAAAGAAAAQsSVTLYGSADAGVGYVNGGAAGAGADGETGL--------DSNSRIGFGGSEELDNGLG--FGASFE 71
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   90 VENTSGSGDTFKARNTYLGAKTNFGTVLAGRNDTVFKQAEGGVDVFGNTNADIDRMLGG-------QVRSGDGVWYYSPK 162
Cdd:pfam13609  72 LEAGFNGAGGFNNRQAYVGLSGGFGTVTLGRQDGAFDEAGVDYDFDGGSLGDSGYDGSGlsgsagfDGRDSNSIIYYSPK 151
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  163 IADLiTLNATYLMEDNYATYDANGNE---IDKDNMYALSATIgdkKLKAQNYYAAIAY---NKAIGGIDAYRAVGQVKLG 236
Cdd:pfam13609 152 FGGF-TAGASYAFGEDGNTNGNNGGVagdSNDTDGYGLGAGY---DFGGVGFSVAAAYqqtDNEGGDQDAWGLGASYSLG 227
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  237 DFKLGGLFQNSE-SIVDGSDDNNTYFVNVVYNLNGVNLKLQYGYDEagfgkyykalgDNAGTDIEVTNITVGADYRVAKS 315
Cdd:pfam13609 228 AFTLGASYADIDdDGAAAGADDNGYGVGATYTVGALTVGAAYGRYD-----------DAGGGDADATQYGLGADYNLSKR 296
                         330
                  ....*....|...
gi 655375068  316 TLLFAHYANYQGE 328
Cdd:pfam13609 297 TTLYAEYAYTDND 309
gram_neg_porins cd00342
Porins form aqueous channels for the diffusion of small hydrophillic molecules across the ...
27-352 2.26e-29

Porins form aqueous channels for the diffusion of small hydrophillic molecules across the outer membrane. Individual 16-strand anti-parallel beta-barrels form a central pore, and trimerizes thru mainly hydrophobic interactions at the interface. Trimers are stabilized by hytrophillic clamping of Loop L2. Loop 3 bends into the pore, creating an elliptical constriction of about 7 x 11A, large enough to allow passage of a glucose molecule without steric hindrance. Removal of the C-terminal residue (usuallly F) destabilizes the trimer and removal of the 16th beta-sheet abolishes trimerization. Unlike typical membrane proteins, porins lack long hydrophobic stretches. Short turns are found at the smooth, periplasmic end, longer irregular loops are found at the rough, extracellular end. C-terminal residue forms salt bridge with N-terminus.


Pssm-ID: 238208 [Multi-domain]  Cd Length: 329  Bit Score: 115.16  E-value: 2.26e-29
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  27 TLYGRLDLSITNSDQGATLQTGtngvevgeSGTYIENNFSHLGVKGSEKISDGVDIIYQMEFQVENTSGS---GDTFKAR 103
Cdd:cd00342    4 TLYGRIDAGVEYVNNAGGGGAG--------QMTSGGNNGSRWGLRGSEDLGGGLKAIFQLESGFNLNTGAlgqGGRLFGR 75
                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 104 NTYLGAKTN-FGTVLAGRNDTVFKQAEGGVDVFGNTNADI----DRMLGGQVRSGDGVWYYSPKIADLiTLNATYLMEDn 178
Cdd:cd00342   76 QAYVGLSSDtYGTLTLGRQYTPLYDVLGTTDPFGGSGGGSapgdGDNLAGTGRANNSVKYTSPFFGGL-TFGAMYAFGN- 153
                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 179 yatydaNGNEIDKDNMYALSATIGDKKLKA-----QNYYAAIAYNKAIGG--IDAYRAVGQVKLGDFKLGGLFQNSE--- 248
Cdd:cd00342  154 ------QAGSTSNGRGYGAGLSYENGPLSLgaaydQQRNGGGAAGGAAGAtsQRAYGAGASYDFGGLKLGAGYTNTRndn 227
                        250       260       270       280       290       300       310       320
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 249 SIVDGSDDNNTYFVNVVYNLNGvNLKLQYGYdeagfgkYYKALGDNAGTDIEVTNITVGADYRVAKSTLLFAHYA----- 323
Cdd:cd00342  228 GGGGGSAKFNGYELGATYQLTP-ALRLGAAY-------YYTKDRNDGGGDGKANQVALGADYALSKRTDLYAEYGyqkns 299
                        330       340       350
                 ....*....|....*....|....*....|
gi 655375068 324 -NYQGEYKDAGAKFDLEDDNVFTVGVRYDF 352
Cdd:cd00342  300 gGASTGLAGGGGPSSGNNQDGVAVGIRHKF 329
 
Name Accession Description Interval E-value
OmpC COG3203
Outer membrane porin OmpC/OmpF/PhoE [Cell wall/membrane/envelope biogenesis];
4-352 1.10e-36

Outer membrane porin OmpC/OmpF/PhoE [Cell wall/membrane/envelope biogenesis];


Pssm-ID: 442436 [Multi-domain]  Cd Length: 336  Bit Score: 135.13  E-value: 1.10e-36
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   4 TLISASVATVLAAASFGAlaDGPTLYGRLDLSITNSD-QGATLQTGTNGVevgesgtyieNNFSHLGVKGSEKISDGVDI 82
Cdd:COG3203    1 TLLALAVAAALAGAAHAQ--SSVTLYGRVDAGVEYVDnGGGSLTRLTSGG----------DSGSRLGFKGSEDLGGGLKA 68
                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  83 IYQMEFQVEN---TSGSGDTFKARNTYLGAK-TNFGTVLAGRNDTVFKQAEGGVDVFGNT----NADIDRMLGGQVRSGD 154
Cdd:COG3203   69 IFQLESGFNAdtgTSGGGGRLFGRQAYVGLKgDDFGTLTLGRQYTPLYDVVGAFDPFGDSgdagNLAGDDNLAGTGRADN 148
                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 155 GVWYYSPKIADLiTLNATYLMEDNYATYDANgneidkdNMYALSATigdkkLKAQNYYAAIAYNKAIGG---------ID 225
Cdd:COG3203  149 AIKYRSPNFGGL-TFGAQYSFGEDAGSSSNG-------RGYGAGLT-----YANGPLSLGAAYQQSNDAqgataggddAD 215
                        250       260       270       280       290       300       310       320
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 226 AYRAVGQVKLGDFKLGGLFQNSESIVDGSDDN---NTYFVNVVYNLNG-VNLKLQYGYDEagfgkyykalGDNAGTDIEV 301
Cdd:COG3203  216 AWGLGASYDFGNLKLAAGYGQTKNDDAGGAGNakaDGYELGASYPFGPaLTLSASYGYTD----------AKDGADDDDA 285
                        330       340       350       360       370
                 ....*....|....*....|....*....|....*....|....*....|.
gi 655375068 302 TNITVGADYRVAKSTLLFAHYANYQGEYKDAGAKFDLEDDNVFTVGVRYDF 352
Cdd:COG3203  286 NQYALGADYALSKRTSLYAEYGYNDNDGNANFTAAAGDTDDGVAVGLRHKF 336
Porin_4 pfam13609
Gram-negative porin;
11-328 3.04e-32

Gram-negative porin;


Pssm-ID: 433346 [Multi-domain]  Cd Length: 311  Bit Score: 122.55  E-value: 3.04e-32
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   11 ATVLAAASFGALAD-GPTLYGRLDLSITNSDQGATLQTGTNGVEVgesgtyieNNFSHLGVKGSEKISDGVDiiYQMEFQ 89
Cdd:pfam13609   2 LAALAAAAGAAAAQsSVTLYGSADAGVGYVNGGAAGAGADGETGL--------DSNSRIGFGGSEELDNGLG--FGASFE 71
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   90 VENTSGSGDTFKARNTYLGAKTNFGTVLAGRNDTVFKQAEGGVDVFGNTNADIDRMLGG-------QVRSGDGVWYYSPK 162
Cdd:pfam13609  72 LEAGFNGAGGFNNRQAYVGLSGGFGTVTLGRQDGAFDEAGVDYDFDGGSLGDSGYDGSGlsgsagfDGRDSNSIIYYSPK 151
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  163 IADLiTLNATYLMEDNYATYDANGNE---IDKDNMYALSATIgdkKLKAQNYYAAIAY---NKAIGGIDAYRAVGQVKLG 236
Cdd:pfam13609 152 FGGF-TAGASYAFGEDGNTNGNNGGVagdSNDTDGYGLGAGY---DFGGVGFSVAAAYqqtDNEGGDQDAWGLGASYSLG 227
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  237 DFKLGGLFQNSE-SIVDGSDDNNTYFVNVVYNLNGVNLKLQYGYDEagfgkyykalgDNAGTDIEVTNITVGADYRVAKS 315
Cdd:pfam13609 228 AFTLGASYADIDdDGAAAGADDNGYGVGATYTVGALTVGAAYGRYD-----------DAGGGDADATQYGLGADYNLSKR 296
                         330
                  ....*....|...
gi 655375068  316 TLLFAHYANYQGE 328
Cdd:pfam13609 297 TTLYAEYAYTDND 309
gram_neg_porins cd00342
Porins form aqueous channels for the diffusion of small hydrophillic molecules across the ...
27-352 2.26e-29

Porins form aqueous channels for the diffusion of small hydrophillic molecules across the outer membrane. Individual 16-strand anti-parallel beta-barrels form a central pore, and trimerizes thru mainly hydrophobic interactions at the interface. Trimers are stabilized by hytrophillic clamping of Loop L2. Loop 3 bends into the pore, creating an elliptical constriction of about 7 x 11A, large enough to allow passage of a glucose molecule without steric hindrance. Removal of the C-terminal residue (usuallly F) destabilizes the trimer and removal of the 16th beta-sheet abolishes trimerization. Unlike typical membrane proteins, porins lack long hydrophobic stretches. Short turns are found at the smooth, periplasmic end, longer irregular loops are found at the rough, extracellular end. C-terminal residue forms salt bridge with N-terminus.


Pssm-ID: 238208 [Multi-domain]  Cd Length: 329  Bit Score: 115.16  E-value: 2.26e-29
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  27 TLYGRLDLSITNSDQGATLQTGtngvevgeSGTYIENNFSHLGVKGSEKISDGVDIIYQMEFQVENTSGS---GDTFKAR 103
Cdd:cd00342    4 TLYGRIDAGVEYVNNAGGGGAG--------QMTSGGNNGSRWGLRGSEDLGGGLKAIFQLESGFNLNTGAlgqGGRLFGR 75
                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 104 NTYLGAKTN-FGTVLAGRNDTVFKQAEGGVDVFGNTNADI----DRMLGGQVRSGDGVWYYSPKIADLiTLNATYLMEDn 178
Cdd:cd00342   76 QAYVGLSSDtYGTLTLGRQYTPLYDVLGTTDPFGGSGGGSapgdGDNLAGTGRANNSVKYTSPFFGGL-TFGAMYAFGN- 153
                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 179 yatydaNGNEIDKDNMYALSATIGDKKLKA-----QNYYAAIAYNKAIGG--IDAYRAVGQVKLGDFKLGGLFQNSE--- 248
Cdd:cd00342  154 ------QAGSTSNGRGYGAGLSYENGPLSLgaaydQQRNGGGAAGGAAGAtsQRAYGAGASYDFGGLKLGAGYTNTRndn 227
                        250       260       270       280       290       300       310       320
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068 249 SIVDGSDDNNTYFVNVVYNLNGvNLKLQYGYdeagfgkYYKALGDNAGTDIEVTNITVGADYRVAKSTLLFAHYA----- 323
Cdd:cd00342  228 GGGGGSAKFNGYELGATYQLTP-ALRLGAAY-------YYTKDRNDGGGDGKANQVALGADYALSKRTDLYAEYGyqkns 299
                        330       340       350
                 ....*....|....*....|....*....|
gi 655375068 324 -NYQGEYKDAGAKFDLEDDNVFTVGVRYDF 352
Cdd:cd00342  300 gGASTGLAGGGGPSSGNNQDGVAVGIRHKF 329
Porin_1 pfam00267
Gram-negative porin;
56-352 2.25e-07

Gram-negative porin;


Pssm-ID: 395205  Cd Length: 335  Bit Score: 52.06  E-value: 2.25e-07
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068   56 ESGTYIENNFSHLGVKGSEKISDGVDIIYQME--FQVENTSGSGDTFKARNTYLGAKT-NFGTVLAGRNDTVFKQAEGGV 132
Cdd:pfam00267  21 RDGSDGDDTYARIGFKGETQINDQLTGYGQWEynVSVNGTEGASTQWGTRLAFAGLKFgDFGSFDYGRNYGVLYDVGAWT 100
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  133 DVF----GNTNADIDRMLGGQVR----------SG--DGVWY---YSPKIADLITLNATYLMEDNY---ATYDaNGNEID 190
Cdd:pfam00267 101 DVLpefgGDTTAQTDNFMTGRANgvatyrnpdfFGlvDGLNFalqYQGKNEDTPARNLTKSNGDGYgvsLNYD-NGGGFG 179
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  191 KDNMYALSATIGDKKLKAQNYYAAIAYNKAiggIDAYRAVGQVKLGDFKLGGLF---QNSESIVDGSDDNNTYFVNVVyn 267
Cdd:pfam00267 180 YGGAYARSDRTGDQKIEYYSIASLTGNGKK---AEVWRLGGKYDANNIYLAAAYaqtRNATRYGAMGFANKTQNTEVV-- 254
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 655375068  268 lngvnlkLQYGYDeagFG-----KYYKALG---DNAGTDIEVTN-ITVGADYRVAKSTLLFAHYANYQgeyKDAGAKFDL 338
Cdd:pfam00267 255 -------AQYQFD---FGlrpsiSYAQSKGkdlEGAYGDNDLVKyVDVGATYYFNKNMSTYVDYKINL---LDKGDDLGI 321
                         330
                  ....*....|....
gi 655375068  339 EDDNVFTVGVRYDF 352
Cdd:pfam00267 322 NTDDAVAVGLRYQF 335
 
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