1gtp: Difference between revisions
New page: left|200px<br /><applet load="1gtp" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gtp, resolution 3.0Å" /> '''GTP CYCLOHYDROLASE I'... |
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== | ==GTP CYCLOHYDROLASE I== | ||
BACKGROUND: Tetrahydrobiopterin serves as the cofactor for enzymes | <StructureSection load='1gtp' size='340' side='right'caption='[[1gtp]], [[Resolution|resolution]] 3.00Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1gtp]] is a 20 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. The August 2015 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Tetrahydrobiopterin Biosynthesis'' by David Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2015_8 10.2210/rcsb_pdb/mom_2015_8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GTP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1GTP FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1gtp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gtp OCA], [https://pdbe.org/1gtp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1gtp RCSB], [https://www.ebi.ac.uk/pdbsum/1gtp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1gtp ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/GCH1_ECOLI GCH1_ECOLI] | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/gt/1gtp_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1gtp ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
BACKGROUND: Tetrahydrobiopterin serves as the cofactor for enzymes involved in neurotransmitter biosynthesis and as regulatory factor in immune cell proliferation and the biosynthesis of melanin. The biosynthetic pathway to tetrahydrobiopterin consists of three steps starting from GTP. The initial reaction is catalyzed by GTP cyclohdrolase I (GTP-CH-I) and involves the chemically complex transformation of the purine into the pterin ring system. RESULTS: The crystal structure of the Escherichia coli GTP-CH-I was solved by single isomorphous replacement and molecular averaging at 3.0 A resolution. The functional enzyme is a homodecameric complex with D5 symmetry, forming a torus with dimensions 65 A x 100 A. The pentameric subunits are constructed via an unprecedented cyclic arrangement of the four-stranded antiparallel beta-sheets of the five monomers to form a 20-stranded antiparallel beta-barrel of 35 A diameter. Two pentamers are tightly associated by intercalation of two antiparallel helix pairs positioned close to the subunit N termini. The C-terminal domain of the GTP-CH-I monomer is topologically identical to a subunit of the homohexameric 6-pyruvoyl tetrahydropterin synthase, the enzyme catalyzing the second step in tetrahydrobiopterin biosynthesis. CONCLUSIONS: The active site of GTP-CH-I is located at the interface of three subunits. It represents a novel GTP-binding site, distinct from the one found in G proteins, with a catalytic apparatus that suggest involvement of histidines and, possibly, a cystine in the unusual reaction mechanism. Despite the lack of significant sequence homology between GTP-CH-I and 6-pyruvoyl tetrahydropterin synthase, the two proteins, which catalyze consecutive steps in tetrahydrobiopterin biosynthesis, share a common subunit fold and oligomerization mode. In addition, the active centres have an identical acceptor site for the 2-amino-4-oxo pyrimidine moiety of their substrates which suggests an evolutionarily conserved protein fold designed for pterin biosynthesis. | |||
Atomic structure of GTP cyclohydrolase I.,Nar H, Huber R, Meining W, Schmid C, Weinkauf S, Bacher A Structure. 1995 May 15;3(5):459-66. PMID:7663943<ref>PMID:7663943</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1gtp" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Cyclohydrolase 3D structures|Cyclohydrolase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: RCSB PDB Molecule of the Month]] | ||
[[Category: Bacher | [[Category: Tetrahydrobiopterin Biosynthesis]] | ||
[[Category: Huber | [[Category: Bacher A]] | ||
[[Category: Meining | [[Category: Huber R]] | ||
[[Category: Nar | [[Category: Meining W]] | ||
[[Category: Nar H]] | |||
