1wm9: Difference between revisions
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[[Image:1wm9.gif|left|200px]] | [[Image:1wm9.gif|left|200px]] | ||
'''Structure of GTP cyclohydrolase I from Thermus thermophilus HB8''' | {{Structure | ||
|PDB= 1wm9 |SIZE=350|CAPTION= <scene name='initialview01'>1wm9</scene>, resolution 2.2Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=ZN:ZINC ION'>ZN</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/GTP_cyclohydrolase_I GTP cyclohydrolase I], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.4.16 3.5.4.16] | |||
|GENE= | |||
}} | |||
'''Structure of GTP cyclohydrolase I from Thermus thermophilus HB8''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1WM9 is a [ | 1WM9 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WM9 OCA]. | ||
==Reference== | ==Reference== | ||
Novel reaction mechanism of GTP cyclohydrolase I. High-resolution X-ray crystallography of Thermus thermophilus HB8 enzyme complexed with a transition state analogue, the 8-oxoguanine derivative., Tanaka Y, Nakagawa N, Kuramitsu S, Yokoyama S, Masui R, J Biochem. 2005 Sep;138(3):263-75. PMID:[http:// | Novel reaction mechanism of GTP cyclohydrolase I. High-resolution X-ray crystallography of Thermus thermophilus HB8 enzyme complexed with a transition state analogue, the 8-oxoguanine derivative., Tanaka Y, Nakagawa N, Kuramitsu S, Yokoyama S, Masui R, J Biochem. 2005 Sep;138(3):263-75. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16169877 16169877] | ||
[[Category: GTP cyclohydrolase I]] | [[Category: GTP cyclohydrolase I]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: riken structural genomics/proteomics initiative]] | [[Category: riken structural genomics/proteomics initiative]] | ||
[[Category: rsgi]] | [[Category: rsgi]] | ||
[[Category: structural | [[Category: structural genomic]] | ||
[[Category: tetrahydrobiopterin]] | [[Category: tetrahydrobiopterin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 14:58:48 2008'' | ||
Revision as of 15:58, 20 March 2008
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| , resolution 2.2Å | |||||||
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| Ligands: | |||||||
| Activity: | GTP cyclohydrolase I, with EC number 3.5.4.16 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of GTP cyclohydrolase I from Thermus thermophilus HB8
OverviewOverview
GTP cyclohydrolase I (GTPCH1) catalyzes the conversion of GTP to dihydroneopterin 3'-triphosphate. We found that an 8-oxoguanine derivative of GTP (8-oxo-GTP) strongly bound to GTPCH1 from Thermus thermophilus HB8 (tGTPCH1) as a competitive inhibitor. The affinity of 8-oxo-GTP was three orders of magnitude greater than that of GTP. These results suggest that 8-oxo-GTP is a transition state analogue of GTPCH1. We have solved the X-ray crystal structures of tGTPCH1 complexed with 8-oxo-GTP and 8-oxo-dGTP at 2.0 and 1.8 A resolution, respectively, as well as the free form of the enzyme at 2.2 A resolution. In the structure of tGTPCH1 complexed with 8-oxo-GTP or 8-oxo-dGTP, the oxygen atoms at O8 of the 8-oxoguanine groups, together with residues Cys108, His111 and Cys179, are coordinated to the zinc ion. The water molecule between Ndelta1 of His177 and N7 of 8-oxoguanine is conserved in both structures. These structural data are in accordance with one of the proposed transition states. Superimpositioning of the structures indicates the imidazole ring of His110 is rotated, implying concomitant proton transfer to the ribose ring O4'. Based on these structural data we propose a novel reaction mechanism for GTPCH1.
About this StructureAbout this Structure
1WM9 is a Single protein structure of sequence from Thermus thermophilus. Full crystallographic information is available from OCA.
ReferenceReference
Novel reaction mechanism of GTP cyclohydrolase I. High-resolution X-ray crystallography of Thermus thermophilus HB8 enzyme complexed with a transition state analogue, the 8-oxoguanine derivative., Tanaka Y, Nakagawa N, Kuramitsu S, Yokoyama S, Masui R, J Biochem. 2005 Sep;138(3):263-75. PMID:16169877
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