3cra
From Proteopedia
Crystal Structure of Escherichia coli MazG, the Regulator of Nutritional Stress Response
Overview
MazG is a nucleoside triphosphate pyrophosphohydrolase that hydrolyzes all canonical nucleoside triphosphates. mazG gene located downstream from mazEF - chromosomal "addiction module", mediated programmed cell death in E. coli. MazG activity is inhibited by MazEF complex both in vivo and in vitro. Enzymatic activity of MazG in vivo affects the cellular level of guanosine 3',5'-bispyrophosphate (ppGpp), synthesized by RelA under amino-acid starvation. The reduction of ppGpp, caused by MazG, may extend the period of cell survival under nutritional stress. Here we describe the first crystal structure of active MazG from E. coli, which is composed of two similarly folded globular domains in tandem. Among two putative catalytic domains, only the Cterminal domain has well-ordered active sites and exhibits an NTPase activity, which are derived from the tightly formed 'additional region'. The MazG-ATP complex structure and subsequent mutagenesis studies explain the peculiar active site environment accommodating all eight canonical NTPs as substrates. In vivo nutrient starvation experiments show that the C-terminus NTPase activity is responsible for the regulation of bacterial cell survival under nutritional stress.
About this Structure
3CRA is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystal structure of Escherichia coli MazG, the regulator of nutritional stress response., Lee S, Kim MH, Kang BS, Kim JS, Kim GH, Kim YG, Kim KJ, J Biol Chem. 2008 Mar 18;. PMID:18353782 Page seeded by OCA on Thu Apr 24 09:55:07 2008
