1wuq
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1wuq.gif|left|200px]] | [[Image:1wuq.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1wuq", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | | | + | --> |
| - | | | + | {{STRUCTURE_1wuq| PDB=1wuq | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''Structure of GTP cyclohydrolase I Complexed with 8-oxo-GTP''' | '''Structure of GTP cyclohydrolase I Complexed with 8-oxo-GTP''' | ||
| Line 32: | Line 29: | ||
[[Category: Tanaka, Y.]] | [[Category: Tanaka, Y.]] | ||
[[Category: Yokoyama, S.]] | [[Category: Yokoyama, S.]] | ||
| - | [[Category: | + | [[Category: Beta barrel]] |
| - | [[Category: | + | [[Category: Hydrolase]] |
| - | [[Category: | + | [[Category: National project on protein structural and functional analyse]] |
| - | [[Category: | + | [[Category: Nppsfa]] |
| - | [[Category: | + | [[Category: Protein-inhibitor complex]] |
| - | [[Category: | + | [[Category: Pteridine]] |
| - | [[Category: | + | [[Category: Riken structural genomics/proteomics initiative]] |
| - | [[Category: | + | [[Category: Rsgi]] |
| - | [[Category: | + | [[Category: Structural genomic]] |
| - | [[Category: | + | [[Category: Tetrahydrobiopterin]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 14:09:53 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 11:09, 3 May 2008
Structure of GTP cyclohydrolase I Complexed with 8-oxo-GTP
Overview
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 Structure
1WUQ is a Single protein structure of sequence from Thermus thermophilus. Full crystallographic information is available from OCA.
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:16169877 Page seeded by OCA on Sat May 3 14:09:53 2008
Categories: GTP cyclohydrolase I | Single protein | Thermus thermophilus | Kuramitsu, S. | Masui, R. | Nakagawa, N. | RSGI, RIKEN Structural Genomics/Proteomics Initiative. | Tanaka, Y. | Yokoyama, S. | Beta barrel | Hydrolase | National project on protein structural and functional analyse | Nppsfa | Protein-inhibitor complex | Pteridine | Riken structural genomics/proteomics initiative | Rsgi | Structural genomic | Tetrahydrobiopterin
