This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.




1gin

From Proteopedia

Revision as of 07:40, 3 February 2008 by OCA (Talk | contribs)
Jump to: navigation, search
Image:1gin.jpg

1gin, resolution 2.8Å

Drag the structure with the mouse to rotate

CRYSTAL STRUCTURE OF ADENYLOSUCCINATE SYNTHETASE FROM ESCHERICHIA COLI COMPLEXED WITH GDP, IMP, HADACIDIN, NO3-, AND MG2+. DATA COLLECTED AT 298K (PH 6.5).

Overview

Crystal structures of adenylosuccinate synthetase from Esherichia coli, complexed with Mg2+, IMP, GDP, NO3- and hadacidin at 298 and 100 K have, been refined to R-factors of 0.188 and 0.206 against data to 2.8 A and 2.5, A resolution, respectively. Conformational changes of up to 9 A relative, to the unligated enzyme occur in loops that bind to Mg2+, GDP, IMP and, hadacidin. Mg2+ binds directly to GDP, NO3-, hadacidin and the protein, but is only five-coordinated. Asp13, which approaches, but does not occupy, the sixth coordination site of Mg2+, hydrogen bonds to N1 of IMP. The, nitrogen atom of NO3- is approximately 2.7 A from O6 of IMP, reflecting a, strong electrostatic interaction between the electron-deficient nitrogen, atom and the electron-rich O6. The spatial relationships between GDP, NO3-, and Mg2+ suggest an interaction between the beta,gamma-bridging oxygen, atom of GTP and Mg2+ in the enzyme-substrate complex. His41 hydrogen bonds, to the beta-phosphate group of GDP and approaches bound NO3-. The aldehyde, group of hadacidin coordinates to the Mg2+, while its carboxyl group, interacts with backbone amide groups 299 to 303 and the side-chain of, Arg303. The 5'-phosphate group of IMP interacts with Asn38, Thr129, Thr239, and Arg143 (from a monomer related by 2-fold symmetry). A mechanism is, proposed for the two-step reaction governed by the synthetase, in which, His41 and Asp13 are essential catalytic side-chains.

About this Structure

1GIN is a Single protein structure of sequence from Escherichia coli with , , , and as ligands. Active as Adenylosuccinate synthase, with EC number 6.3.4.4 Known structural/functional Sites: , and . Full crystallographic information is available from OCA.

Reference

Crystal structures of adenylosuccinate synthetase from Escherichia coli complexed with GDP, IMP hadacidin, NO3-, and Mg2+., Poland BW, Fromm HJ, Honzatko RB, J Mol Biol. 1996 Dec 20;264(5):1013-27. PMID:9000627

Page seeded by OCA on Sun Feb 3 09:40:24 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1gin"
Personal tools