1usy
From Proteopedia
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ATP PHOSPHORIBOSYL TRANSFERASE (HISG:HISZ) COMPLEX FROM THERMOTOGA MARITIMA
Overview
The molecular structure of the ATP phosphoribosyl transferase from the, hyperthermophile Thermotoga maritima is composed of a 220 kDa, hetero-octameric complex comprising four catalytic subunits (HisGS) and, four regulatory subunits (HisZ). Steady-state kinetics indicate that only, the complete octameric complex is active and non-competitively inhibited, by the pathway product histidine. The rationale for these findings is, provided by the crystal structure revealing a total of eight histidine, binding sites that are located within each of the four HisGS-HisZ subunit, interfaces formed by the ATP phosphoribosyl transferase complex. While the, structure of the catalytic HisGS subunit is related to the catalytic, domain of another family of (HisGL)2 ATP phosphoribosyl transferases that, is functional in the absence of additional regulatory subunits, the, structure of the regulatory HisZ subunit is distantly related to class II, aminoacyl-tRNA synthetases. However, neither the mode of the oligomeric, subunit arrangement nor the type of histidine binding pockets is found in, these structural relatives. Common ancestry of the regulatory HisZ subunit, and class II aminoacyl-tRNA synthetase may reflect the balanced need of, regulated amounts of a cognate amino acid (histidine) in the translation, apparatus, ultimately linking amino acid biosynthesis and protein, biosynthesis in terms of function, structure and evolution.
About this Structure
1USY is a Protein complex structure of sequences from Thermotoga maritima with PO4, HIS and HIS as ligands. Active as ATP phosphoribosyltransferase, with EC number 2.4.2.17 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Regulation of the hetero-octameric ATP phosphoribosyl transferase complex from Thermotoga maritima by a tRNA synthetase-like subunit., Vega MC, Zou P, Fernandez FJ, Murphy GE, Sterner R, Popov A, Wilmanns M, Mol Microbiol. 2005 Feb;55(3):675-86. PMID:15660995
Page seeded by OCA on Mon Nov 5 17:10:50 2007
