Tunnelling fold (T-fold) family protein such as dihydroneopterin-triphosphate epimerase (DHNTPE), dihydroneopterin aldolase (DHNA) , GTP cyclohydrolase I (GTPCH-1), 6-pyrovoyl tetrahydropterin synthetase (PTPS), and uricase (UO,uroate/urate oxidase)
Tunnelling fold (T-fold). The five known T-folds are found in five different enzymes with ...
39-219
1.92e-103
Tunnelling fold (T-fold). The five known T-folds are found in five different enzymes with different functions: dihydroneopterin-triphosphate epimerase (DHNTPE), dihydroneopterin aldolase (DHNA) , GTP cyclohydrolase I (GTPCH-1), 6-pyrovoyl tetrahydropterin synthetase (PTPS), and uricase (UO,uroate/urate oxidase). They bind to substrates belonging to the purine or pterin families, and share a fold-related binding site with a glutamate or glutamine residue anchoring the substrate and a lot of conserved interactions. They also share a similar oligomerization mode: several T-folds join together to form a beta(2n)alpha(n) barrel, then two barrels join together in a head-to-head fashion to made up the native enzymes. The functional enzyme is a tetramer for UO, a hexamer for PTPS, an octamer for DHNA/DHNTPE and a decamer for GTPCH-1. The substrate is located in a deep and narrow pocket at the interface between monomers. In PTPS, the active site is located at the interface of three monomers, two from one trimer and one from the other trimer. In GTPCH-1, it is also located at the interface of three subunits, two from one pentamer and one from the other pentamer. There are four equivalent active sites in UO, six in PTPS, eight in DHNA/DHNTPE and ten in GTPCH-1. Each globular multimeric enzyme encloses a tunnel which is lined with charged residues for DHNA and UO, and with basic residues in PTPS. The N and C-terminal ends are located on one side of the T-fold while the residues involved in the catalytic activity are located at the opposite side. In PTPS, UO and DHNA/DHNTPE, the N and C-terminal extremities of the enzyme are located on the exterior side of the functional multimeric enzyme. In GTPCH-1, the extra C-terminal helix places the extremity inside the tunnel.
The actual alignment was detected with superfamily member TIGR00063:
Pssm-ID: 469697 [Multi-domain] Cd Length: 180 Bit Score: 296.28 E-value: 1.92e-103
GTP cyclohydrolase I; alternate names: Punch (Drosophila),GTP cyclohydrolase I (EC 3.5.4.16) catalyzes the biosynthesis of formic acid and dihydroneopterin triphosphate from GTP. This reaction is the first step in the biosynthesis of tetrahydrofolate in prokaryotes, of tetrahydrobiopterin in vertebrates, and of pteridine-containing pigments in insects. [Biosynthesis of cofactors, prosthetic groups, and carriers, Folic acid]
Pssm-ID: 129173 [Multi-domain] Cd Length: 180 Bit Score: 296.28 E-value: 1.92e-103
GTP cyclohydrolase I (GTP-CH-I) catalyzes the conversion of GTP into dihydroneopterin ...
35-219
3.16e-93
GTP cyclohydrolase I (GTP-CH-I) catalyzes the conversion of GTP into dihydroneopterin triphosphate. The enzyme product is the precursor of tetrahydrofolate in eubacteria, fungi, and plants and of the folate analogs in methanogenic bacteria. In vertebrates and insects it is the biosynthtic precursor of tetrahydrobiopterin (BH4) which is involved in the formation of catacholamines, nitric oxide, and the stimulation of T lymphocytes. The biosynthetic reaction of BH4 is controlled by a regulatory protein GFRP which mediates feedback inhibition of GTP-CH-I by BH4. This inhibition is reversed by phenylalanine. The decameric GTP-CH-I forms a complex with two pentameric GFRP in the presence of phenylalanine or a combination of GTP and BH4, respectively.
Pssm-ID: 238349 [Multi-domain] Cd Length: 185 Bit Score: 270.79 E-value: 3.16e-93
GTP cyclohydrolase I; alternate names: Punch (Drosophila),GTP cyclohydrolase I (EC 3.5.4.16) catalyzes the biosynthesis of formic acid and dihydroneopterin triphosphate from GTP. This reaction is the first step in the biosynthesis of tetrahydrofolate in prokaryotes, of tetrahydrobiopterin in vertebrates, and of pteridine-containing pigments in insects. [Biosynthesis of cofactors, prosthetic groups, and carriers, Folic acid]
Pssm-ID: 129173 [Multi-domain] Cd Length: 180 Bit Score: 296.28 E-value: 1.92e-103
GTP cyclohydrolase I (GTP-CH-I) catalyzes the conversion of GTP into dihydroneopterin ...
35-219
3.16e-93
GTP cyclohydrolase I (GTP-CH-I) catalyzes the conversion of GTP into dihydroneopterin triphosphate. The enzyme product is the precursor of tetrahydrofolate in eubacteria, fungi, and plants and of the folate analogs in methanogenic bacteria. In vertebrates and insects it is the biosynthtic precursor of tetrahydrobiopterin (BH4) which is involved in the formation of catacholamines, nitric oxide, and the stimulation of T lymphocytes. The biosynthetic reaction of BH4 is controlled by a regulatory protein GFRP which mediates feedback inhibition of GTP-CH-I by BH4. This inhibition is reversed by phenylalanine. The decameric GTP-CH-I forms a complex with two pentameric GFRP in the presence of phenylalanine or a combination of GTP and BH4, respectively.
Pssm-ID: 238349 [Multi-domain] Cd Length: 185 Bit Score: 270.79 E-value: 3.16e-93
Tunnelling fold (T-fold). The five known T-folds are found in five different enzymes with ...
96-189
8.78e-09
Tunnelling fold (T-fold). The five known T-folds are found in five different enzymes with different functions: dihydroneopterin-triphosphate epimerase (DHNTPE), dihydroneopterin aldolase (DHNA) , GTP cyclohydrolase I (GTPCH-1), 6-pyrovoyl tetrahydropterin synthetase (PTPS), and uricase (UO,uroate/urate oxidase). They bind to substrates belonging to the purine or pterin families, and share a fold-related binding site with a glutamate or glutamine residue anchoring the substrate and a lot of conserved interactions. They also share a similar oligomerization mode: several T-folds join together to form a beta(2n)alpha(n) barrel, then two barrels join together in a head-to-head fashion to made up the native enzymes. The functional enzyme is a tetramer for UO, a hexamer for PTPS, an octamer for DHNA/DHNTPE and a decamer for GTPCH-1. The substrate is located in a deep and narrow pocket at the interface between monomers. In PTPS, the active site is located at the interface of three monomers, two from one trimer and one from the other trimer. In GTPCH-1, it is also located at the interface of three subunits, two from one pentamer and one from the other pentamer. There are four equivalent active sites in UO, six in PTPS, eight in DHNA/DHNTPE and ten in GTPCH-1. Each globular multimeric enzyme encloses a tunnel which is lined with charged residues for DHNA and UO, and with basic residues in PTPS. The N and C-terminal ends are located on one side of the T-fold while the residues involved in the catalytic activity are located at the opposite side. In PTPS, UO and DHNA/DHNTPE, the N and C-terminal extremities of the enzyme are located on the exterior side of the functional multimeric enzyme. In GTPCH-1, the extra C-terminal helix places the extremity inside the tunnel.
Pssm-ID: 238351 Cd Length: 122 Bit Score: 52.06 E-value: 8.78e-09
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
