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PDBsum entry 3k92

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protein ligands Protein-protein interface(s) links
Oxidoreductase PDB id
3k92
Jmol
Contents
Protein chains
418 a.a. *
396 a.a. *
Ligands
PEG ×5
Waters ×824
* Residue conservation analysis
PDB id:
3k92
Name: Oxidoreductase
Title: Crystal structure of a e93k mutant of the majour bacillus su glutamate dehydrogenase rocg
Structure: NAD-specific glutamate dehydrogenase. Chain: a, b, c, d, e, f. Synonym: NAD-gdh. Engineered: yes. Mutation: yes
Source: Bacillus subtilis. Organism_taxid: 1423. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
2.30Å     R-factor:   0.185     R-free:   0.238
Authors: K.Gunka,J.A.Newman,F.M.Commichau,C.Herzberg,C.Rodrigues,L.He R.J.Lewis,J.Stulke
Key ref: K.Gunka et al. (2010). Functional dissection of a trigger enzyme: mutations of the bacillus subtilis glutamate dehydrogenase RocG that affect differentially its catalytic activity and regulatory properties. J Mol Biol, 400, 815-827. PubMed id: 20630473
Date:
15-Oct-09     Release date:   02-Jun-10    
PROCHECK
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 Headers
 References

Protein chains
Pfam   ArchSchema ?
P39633  (DHE2_BACSU) -  Catabolic NAD-specific glutamate dehydrogenase RocG
Seq:
Struc:
424 a.a.
418 a.a.*
Protein chains
Pfam   ArchSchema ?
P39633  (DHE2_BACSU) -  Catabolic NAD-specific glutamate dehydrogenase RocG
Seq:
Struc:
424 a.a.
396 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 4 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: Chains A, B, C, D, E, F: E.C.1.4.1.2  - Glutamate dehydrogenase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: L-glutamate + H2O + NAD+ = 2-oxoglutarate + NH3 + NADH
L-glutamate
+ H(2)O
+ NAD(+)
= 2-oxoglutarate
+ NH(3)
+ NADH
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     oxidation-reduction process   2 terms 
  Biochemical function     protein binding     4 terms  

 

 
    reference    
 
 
J Mol Biol 400:815-827 (2010)
PubMed id: 20630473  
 
 
Functional dissection of a trigger enzyme: mutations of the bacillus subtilis glutamate dehydrogenase RocG that affect differentially its catalytic activity and regulatory properties.
K.Gunka, J.A.Newman, F.M.Commichau, C.Herzberg, C.Rodrigues, L.Hewitt, R.J.Lewis, J.Stülke.
 
  ABSTRACT  
 
Any signal transduction requires communication between a sensory component and an effector. Some enzymes engage in signal perception and transduction, as well as in catalysis, and these proteins are known as "trigger" enzymes. In this report, we detail the trigger properties of RocG, the glutamate dehydrogenase of Bacillus subtilis. RocG not only deaminates the key metabolite glutamate to form alpha-ketoglutarate but also interacts directly with GltC, a LysR-type transcription factor that regulates glutamate biosynthesis from alpha-ketoglutarate, thus linking the two metabolic pathways. We have isolated mutants of RocG that separate the two functions. Several mutations resulted in permanent inactivation of GltC as long as a source of glutamate was present. These RocG proteins have lost their ability to catabolize glutamate due to a strongly reduced affinity for glutamate. The second class of mutants is exemplified by the replacement of aspartate residue 122 by asparagine. This mutant protein has retained enzymatic activity but has lost the ability to control the activity of GltC. Crystal structures of glutamate dehydrogenases that permit a molecular explanation of the properties of the various mutants are presented. Specifically, we may propose that D122N replacement affects the surface of RocG. Our data provide evidence for a correlation between the enzymatic activity of RocG and its ability to inactivate GltC, and thus give insights into the mechanism that couples the enzymatic activity of a trigger enzyme to its regulatory function.