Database accession: MF7000257
Name: MazG (Escherichia coli)
PDB ID: 3cra
Experimental method: X-ray (2.10 Å)
Assembly: Homodimer
Source organism: Escherichia coli
Primary publication of the structure:
Lee S, Kim MH, Kang BS, Kim JS, Kim GH, Kim YG, Kim KJ
Crystal structure of Escherichia coli MazG, the regulator of nutritional stress response.
(2008) J. Biol. Chem. 283: 15232-40
PMID: 18353782
Abstract:
MazG is a nucleoside triphosphate pyrophosphohydrolase that hydrolyzes all canonical nucleoside triphosphates. The mazG gene located downstream from the chromosomal mazEF "addiction module," that mediated programmed cell death in Escherichia coli. MazG activity is inhibited by the 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 the two putative catalytic domains, only the C-terminal domain has well ordered active sites and exhibits an NTPase activity. 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.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
ATP binding ATP binding
ATP diphosphatase activity ATP diphosphatase activity
metal ion binding metal ion binding
nucleoside triphosphate diphosphatase activity nucleoside triphosphate diphosphatase activity
Biological process:
cellular response to starvation cellular response to starvation
dATP catabolic process dATP catabolic process
dGTP catabolic process dGTP catabolic process
dTTP catabolic process dTTP catabolic process
dUTP catabolic process dUTP catabolic process
TTP catabolic process TTP catabolic process
UTP catabolic process UTP catabolic process
Cellular component: not assigned
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: A, B
Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.
Number of unique protein segments: 1
Name: Nucleoside triphosphate pyrophosphohydrolase
Source organism: Escherichia coli
Length: 263 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMNQIDRLLTIMQRLRDPENGCPWDKEQTFATIAPYTLEETYEVLDAIAREDFDDLRGELGDLLFQVVFYAQMAQEEGRFDFNDICAAISDKLERRHPHVFADSSAENSSEVLARWEQIKTEERAQKAQHSALDDIPRSLPALMRAQKIQKRCANVGFDWTTLGPVVDKVYEEIDEVMYEARQAVVDQAKLEEEMGDLLFATVNLARHLGTKAEIALQKANEKFERRFREVERIVAARGLEMTGVDLETMEEVWQQVKRQEIDL
UniProtKB AC: P0AEY3 (positions: 2-260)
Coverage: 98%
Name: Nucleoside triphosphate pyrophosphohydrolase
Source organism: Escherichia coli
Length: 263 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMNQIDRLLTIMQRLRDPENGCPWDKEQTFATIAPYTLEETYEVLDAIAREDFDDLRGELGDLLFQVVFYAQMAQEEGRFDFNDICAAISDKLERRHPHVFADSSAENSSEVLARWEQIKTEERAQKAQHSALDDIPRSLPALMRAQKIQKRCANVGFDWTTLGPVVDKVYEEIDEVMYEARQAVVDQAKLEEEMGDLLFATVNLARHLGTKAEIALQKANEKFERRFREVERIVAARGLEMTGVDLETMEEVWQQVKRQEIDL
UniProtKB AC: P0AEY3 (positions: 2-261)
Coverage: 98%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: MazG nucleotide pyrophosphohydrolase domain
Evidence level: Direct evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
CD denaturatrion fits two state model. A four-state thermal denaturation model fits all data including DSC in (dimeric N2 native, two dimeric intermadiate I2,S2, and monomeric denatured D states). The authors state that both native like intermediete states are dimeric. Thermally denatured monomeric state is not fully unfolded and contains a significant fraction of residual α-helical structure (PMID:19523960).
Chain A:
N/A
Chain B:
N/A
Surface and contacts features:
Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap). Download the CIF file (.cif)
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