glycoside hydrolase family 18 protein such as chitinase, which catalyzes the random endo-hydrolysis of the 1,4-beta-linkages of N-acetylglucosamine in chitin and chitodextrins
The GH18 (glycosyl hydrolase, family 18) type II chitinases hydrolyze chitin, an abundant ...
25-375
1.46e-102
The GH18 (glycosyl hydrolase, family 18) type II chitinases hydrolyze chitin, an abundant polymer of beta-1,4-linked N-acetylglucosamine (GlcNAc) which is a major component of the cell wall of fungi and the exoskeleton of arthropods. Chitinases have been identified in viruses, bacteria, fungi, protozoan parasites, insects, and plants. The structure of the GH18 domain is an eight-stranded beta/alpha barrel with a pronounced active-site cleft at the C-terminal end of the beta-barrel. The GH18 family includes chitotriosidase, chitobiase, hevamine, zymocin-alpha, narbonin, SI-CLP (stabilin-1 interacting chitinase-like protein), IDGF (imaginal disc growth factor), CFLE (cortical fragment-lytic enzyme) spore hydrolase, the type III and type V plant chitinases, the endo-beta-N-acetylglucosaminidases, and the chitolectins. The GH85 (glycosyl hydrolase, family 85) ENGases (endo-beta-N-acetylglucosaminidases) are closely related to the GH18 chitinases and are included in this alignment model.
The actual alignment was detected with superfamily member cd02872:
Pssm-ID: 471972 [Multi-domain] Cd Length: 362 Bit Score: 310.65 E-value: 1.46e-102
This conserved domain family includes a large number of catalytically inactive chitinase-like ...
25-375
1.46e-102
This conserved domain family includes a large number of catalytically inactive chitinase-like lectins (chitolectins) including YKL-39, YKL-40 (HCGP39), YM1, oviductin, and AMCase (acidic mammalian chitinase), as well as catalytically active chitotriosidases. The conserved domain is an eight-stranded alpha/beta barrel fold belonging to the family 18 glycosyl hydrolases. The fold has a pronounced active-site cleft at the C-terminal end of the beta-barrel. The chitolectins lack a key active site glutamate (the proton donor required for hydrolytic activity) but retain highly conserved residues involved in oligosaccharide binding. Chitotriosidase is a chitinolytic enzyme expressed in maturing macrophages, which suggests that it plays a part in antimicrobial defense. Chitotriosidase hydrolyzes chitotriose, as well as colloidal chitin to yield chitobiose and is therefore considered an exochitinase. Chitotriosidase occurs in two major forms, the large form being converted to the small form by either RNA or post-translational processing. Although the small form, containing the chitinase domain alone, is sufficient for the chitinolytic activity, the additional C-terminal chitin-binding domain of the large form plays a role in processing colloidal chitin. The chitotriosidase gene is nonessential in humans, as about 35% of the population are heterozygous and 6% homozygous for an inactivated form of the gene. HCGP39 is a 39-kDa human cartilage glycoprotein thought to play a role in connective tissue remodeling and defense against pathogens.
Pssm-ID: 119351 [Multi-domain] Cd Length: 362 Bit Score: 310.65 E-value: 1.46e-102
Chitin binding Peritrophin-A domain; This domain is called the Peritrophin-A domain and is ...
394-443
4.56e-05
Chitin binding Peritrophin-A domain; This domain is called the Peritrophin-A domain and is found in chitin binding proteins particularly peritrophic matrix proteins of insects and animal chitinases. Copies of the domain are also found in some baculoviruses. Relevant references that describe proteins with this domain include. It is an extracellular domain that contains six conserved cysteines that probably form three disulphide bridges. Chitin binding has been demonstrated for a protein containing only two of these domains.
Pssm-ID: 426342 [Multi-domain] Cd Length: 53 Bit Score: 40.86 E-value: 4.56e-05
This conserved domain family includes a large number of catalytically inactive chitinase-like ...
25-375
1.46e-102
This conserved domain family includes a large number of catalytically inactive chitinase-like lectins (chitolectins) including YKL-39, YKL-40 (HCGP39), YM1, oviductin, and AMCase (acidic mammalian chitinase), as well as catalytically active chitotriosidases. The conserved domain is an eight-stranded alpha/beta barrel fold belonging to the family 18 glycosyl hydrolases. The fold has a pronounced active-site cleft at the C-terminal end of the beta-barrel. The chitolectins lack a key active site glutamate (the proton donor required for hydrolytic activity) but retain highly conserved residues involved in oligosaccharide binding. Chitotriosidase is a chitinolytic enzyme expressed in maturing macrophages, which suggests that it plays a part in antimicrobial defense. Chitotriosidase hydrolyzes chitotriose, as well as colloidal chitin to yield chitobiose and is therefore considered an exochitinase. Chitotriosidase occurs in two major forms, the large form being converted to the small form by either RNA or post-translational processing. Although the small form, containing the chitinase domain alone, is sufficient for the chitinolytic activity, the additional C-terminal chitin-binding domain of the large form plays a role in processing colloidal chitin. The chitotriosidase gene is nonessential in humans, as about 35% of the population are heterozygous and 6% homozygous for an inactivated form of the gene. HCGP39 is a 39-kDa human cartilage glycoprotein thought to play a role in connective tissue remodeling and defense against pathogens.
Pssm-ID: 119351 [Multi-domain] Cd Length: 362 Bit Score: 310.65 E-value: 1.46e-102
The GH18 (glycosyl hydrolases, family 18) type II chitinases hydrolyze chitin, an abundant ...
97-355
2.02e-44
The GH18 (glycosyl hydrolases, family 18) type II chitinases hydrolyze chitin, an abundant polymer of N-acetylglucosamine and have been identified in bacteria, fungi, insects, plants, viruses, and protozoan parasites. The structure of this domain is an eight-stranded alpha/beta barrel with a pronounced active-site cleft at the C-terminal end of the beta-barrel.
Pssm-ID: 119365 [Multi-domain] Cd Length: 322 Bit Score: 158.18 E-value: 2.02e-44
The IDGF's (imaginal disc growth factors) are a family of growth factors identified in insects ...
24-375
1.58e-36
The IDGF's (imaginal disc growth factors) are a family of growth factors identified in insects that include at least five members, some of which are encoded by genes in a tight cluster. The IDGF's have an eight-stranded alpha/beta barrel fold and are related to the glycosyl hydrolase family 18 (GH18) chitinases, but they have an amino acid substitution known to abolish chitinase catalytic activity. IDGFs may have evolved from chitinases to gain new functions as growth factors, interacting with cell surface glycoproteins involved in growth-promoting processes.
Pssm-ID: 119352 [Multi-domain] Cd Length: 413 Bit Score: 138.99 E-value: 1.58e-36
The GH18 (glycosyl hydrolase, family 18) type II chitinases hydrolyze chitin, an abundant ...
25-213
5.74e-30
The GH18 (glycosyl hydrolase, family 18) type II chitinases hydrolyze chitin, an abundant polymer of beta-1,4-linked N-acetylglucosamine (GlcNAc) which is a major component of the cell wall of fungi and the exoskeleton of arthropods. Chitinases have been identified in viruses, bacteria, fungi, protozoan parasites, insects, and plants. The structure of the GH18 domain is an eight-stranded beta/alpha barrel with a pronounced active-site cleft at the C-terminal end of the beta-barrel. The GH18 family includes chitotriosidase, chitobiase, hevamine, zymocin-alpha, narbonin, SI-CLP (stabilin-1 interacting chitinase-like protein), IDGF (imaginal disc growth factor), CFLE (cortical fragment-lytic enzyme) spore hydrolase, the type III and type V plant chitinases, the endo-beta-N-acetylglucosaminidases, and the chitolectins. The GH85 (glycosyl hydrolase, family 85) ENGases (endo-beta-N-acetylglucosaminidases) are closely related to the GH18 chitinases and are included in this alignment model.
Pssm-ID: 119349 [Multi-domain] Cd Length: 210 Bit Score: 115.94 E-value: 5.74e-30
The class V plant chitinases have a glycosyl hydrolase family 18 (GH18) domain, but lack the ...
32-356
5.63e-29
The class V plant chitinases have a glycosyl hydrolase family 18 (GH18) domain, but lack the chitin-binding domain present in other GH18 enzymes. The GH18 domain of the class V chitinases has endochitinase activity in some cases and no catalytic activity in others. Included in this family is a lectin found in black locust (Robinia pseudoacacia) bark, which binds chitin but lacks chitinase activity. Also included is a chitinase-related receptor-like kinase (CHRK1) from tobacco (Nicotiana tabacum), with an N-terminal GH18 domain and a C-terminal kinase domain, which is thought to be part of a plant signaling pathway. The GH18 domain of CHRK1 is expressed extracellularly where it binds chitin but lacks chitinase activity.
Pssm-ID: 119358 [Multi-domain] Cd Length: 299 Bit Score: 115.54 E-value: 5.63e-29
Cortical fragment-lytic enzyme (CFLE) is a peptidoglycan hydrolase involved in bacterial ...
97-352
5.41e-19
Cortical fragment-lytic enzyme (CFLE) is a peptidoglycan hydrolase involved in bacterial endospore germination. CFLE is expressed as an inactive preprotein (called SleB) in the forespore compartment of sporulating cells. SleB translocates across the forespore inner membrane and is deposited as a mature enzyme in the cortex layer of the spore. As part of a sensory mechanism capable of initiating germination, CFLE degrades a spore-specific peptidoglycan constituent called muramic-acid delta-lactam that comprises the outer cortex. CFLE has a C-terminal glycosyl hydrolase family 18 (GH18) catalytic domain as well as two N-terminal LysM peptidoglycan-binding domains. In addition to SleB, this family includes YaaH, YdhD, and YvbX from Bacillus subtilis.
Pssm-ID: 119353 [Multi-domain] Cd Length: 313 Bit Score: 87.32 E-value: 5.41e-19
Zymocin, alpha subunit. Zymocin is a heterotrimeric enzyme that inhibits yeast cell cycle ...
81-355
1.87e-08
Zymocin, alpha subunit. Zymocin is a heterotrimeric enzyme that inhibits yeast cell cycle progression. The zymocin alpha subunit has a chitinase activity that is essential for holoenzyme action from the cell exterior while the gamma subunit contains the intracellular toxin responsible for G1 phase cell cycle arrest. The zymocin alpha and beta subunits are thought to act from the cell's exterior by docking to the cell wall-associated chitin, thus mediating gamma-toxin translocation. The alpha subunit has an eight-stranded TIM barrel fold similar to that of family 18 glycosyl hydrolases such as hevamine, chitolectin, and chitobiase.
Pssm-ID: 119357 [Multi-domain] Cd Length: 345 Bit Score: 56.16 E-value: 1.87e-08
The Bacteroides thetaiotaomicron protein represented by pdb structure 3CO4 is an ...
97-264
5.11e-07
The Bacteroides thetaiotaomicron protein represented by pdb structure 3CO4 is an uncharacterized bacterial member of the family 18 glycosyl hydrolases with homologs found in Flavobacterium, Stigmatella, and Pseudomonas.
Pssm-ID: 119362 [Multi-domain] Cd Length: 253 Bit Score: 50.91 E-value: 5.11e-07
Chitin binding Peritrophin-A domain; This domain is called the Peritrophin-A domain and is ...
394-443
4.56e-05
Chitin binding Peritrophin-A domain; This domain is called the Peritrophin-A domain and is found in chitin binding proteins particularly peritrophic matrix proteins of insects and animal chitinases. Copies of the domain are also found in some baculoviruses. Relevant references that describe proteins with this domain include. It is an extracellular domain that contains six conserved cysteines that probably form three disulphide bridges. Chitin binding has been demonstrated for a protein containing only two of these domains.
Pssm-ID: 426342 [Multi-domain] Cd Length: 53 Bit Score: 40.86 E-value: 4.56e-05
GH18 domain of an uncharacterized family of bacterial proteins, which share a common ...
102-218
1.91e-04
GH18 domain of an uncharacterized family of bacterial proteins, which share a common three-domain architecture: an N-terminal glycosyl hydrolase family 18 (GH18) domain, a glycosyl transferase family 2 domain, and a C-terminal polysaccharide deacetylase domain.
Pssm-ID: 119366 [Multi-domain] Cd Length: 298 Bit Score: 43.17 E-value: 1.91e-04
GH18 domain of Chitinase D (ChiD). ChiD, a chitinase found in Bacillus circulans, hydrolyzes ...
96-180
2.52e-04
GH18 domain of Chitinase D (ChiD). ChiD, a chitinase found in Bacillus circulans, hydrolyzes the 1,4-beta-linkages of N-acetylglucosamine in chitin and chitodextrins. The domain architecture of ChiD includes a catalytic glycosyl hydrolase family 18 (GH18) domain, a chitin-binding domain, and a fibronectin type III domain. The chitin-binding and fibronectin type III domains are located either N-terminal or C-terminal to the catalytic domain. This family includes exochitinase Chi36 from Bacillus cereus.
Pssm-ID: 119350 [Multi-domain] Cd Length: 312 Bit Score: 43.09 E-value: 2.52e-04
GH18 domain of CTS3 (chitinase 3), an uncharacterized protein from the human fungal pathogen ...
97-153
8.94e-03
GH18 domain of CTS3 (chitinase 3), an uncharacterized protein from the human fungal pathogen Coccidioides posadasii. CTS3 has a chitinase-like glycosyl hydrolase family 18 (GH18) domain; and has homologs in bacteria as well as fungi.
Pssm-ID: 119363 Cd Length: 256 Bit Score: 37.70 E-value: 8.94e-03
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.
of the residues that compose this conserved feature have been mapped to the query sequence.
Click on the triangle to view details about the feature, including a multiple sequence alignment
of your query sequence and the protein sequences used to curate the domain model,
where hash marks (#) above the aligned sequences show the location of the conserved feature residues.
The thumbnail image, if present, provides an approximate view of the feature's location in 3 dimensions.
Click on the triangle for interactive 3D structure viewing options.
Functional characterization of the conserved domain architecture found on the query.
Click here to see more details.
This image shows a graphical summary of conserved domains identified on the query sequence.
The Show Concise/Full Display button at the top of the page can be used to select the desired level of detail: only top scoring hits
(labeled illustration) or all hits
(labeled illustration).
Domains are color coded according to superfamilies
to which they have been assigned. Hits with scores that pass a domain-specific threshold
(specific hits) are drawn in bright colors.
Others (non-specific hits) and
superfamily placeholders are drawn in pastel colors.
if a domain or superfamily has been annotated with functional sites (conserved features),
they are mapped to the query sequence and indicated through sets of triangles
with the same color and shade of the domain or superfamily that provides the annotation. Mouse over the colored bars or triangles to see descriptions of the domains and features.
click on the bars or triangles to view your query sequence embedded in a multiple sequence alignment of the proteins used to develop the corresponding domain model.
The table lists conserved domains identified on the query sequence. Click on the plus sign (+) on the left to display full descriptions, alignments, and scores.
Click on the domain model's accession number to view the multiple sequence alignment of the proteins used to develop the corresponding domain model.
To view your query sequence embedded in that multiple sequence alignment, click on the colored bars in the Graphical Summary portion of the search results page,
or click on the triangles, if present, that represent functional sites (conserved features)
mapped to the query sequence.
Concise Display shows only the best scoring domain model, in each hit category listed below except non-specific hits, for each region on the query sequence.
(labeled illustration) Standard Display shows only the best scoring domain model from each source, in each hit category listed below for each region on the query sequence.
(labeled illustration) Full Display shows all domain models, in each hit category below, that meet or exceed the RPS-BLAST threshold for statistical significance.
(labeled illustration) Four types of hits can be shown, as available,
for each region on the query sequence:
specific hits meet or exceed a domain-specific e-value threshold
(illustrated example)
and represent a very high confidence that the query sequence belongs to the same protein family as the sequences use to create the domain model
non-specific hits
meet or exceed the RPS-BLAST threshold for statistical significance (default E-value cutoff of 0.01, or an E-value selected by user via the
advanced search options)
the domain superfamily to which the specific and non-specific hits belong
multi-domain models that were computationally detected and are likely to contain multiple single domains
Retrieve proteins that contain one or more of the domains present in the query sequence, using the Conserved Domain Architecture Retrieval Tool
(CDART).
Modify your query to search against a different database and/or use advanced search options
