GuaB

• Description: IMP dehydrogenase
  
  

Gene name	guaB
Synonyms	guaA
Essential	yes PubMed
Product	IMP dehydrogenase
Function	biosynthesis of GMP
Gene expression levels in SubtiExpress: GuaB
Metabolic function and regulation of this protein in SubtiPathways: guaB
MW, pI	52 kDa, 6.168
Gene length, protein length	1464 bp, 488 aa
Immediate neighbours	yaaC, dacA
Sequences	Protein DNA DNA_with_flanks
Genetic context This image was kindly provided by SubtiList
Expression at a glance   PubMed

Categories containing this gene/protein

biosynthesis/ acquisition of nucleotides, essential genes, phosphoproteins, most abundant proteins

This gene is a member of the following regulons

CodY regulon

The gene

Basic information

• Locus tag: BSU00090

Phenotypes of a mutant

• essential PubMed
• reduced expression of guaB suppresses the requirement of a relA sasA sasB triple mutant for branched chain amino acids, methionine and threonine PubMed

Database entries

• BsubCyc: BSU00090

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: Inosine 5'-phosphate + NAD⁺ + H₂O = xanthosine 5'-phosphate + NADH (according to Swiss-Prot)

• Protein family: IMPDH/GMPR family (according to Swiss-Prot)

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:
  • phosphorylated (STY) PubMed
  • Cys308 is S-cysteinylated after diamide stress PubMed, PubMed
  • Cys308 is S-bacillithiolated by NaOCl stress in B. subtilis and other Bacillus species PubMed

• Cofactors:

• Effectors of protein activity:
  • inhibition of enzymatic activity by (p)ppGpp during the ´stringent response´PubMed

• Interactions:

• Localization:

Database entries

• BsubCyc: BSU00090

• Structure: 1VRD (from Thermotoga maritima msb8, 60% identity, 80% similarity)

• UniProt: P21879

• KEGG entry: [3]

• E.C. number: 1.1.1.205

Expression and regulation

• Operon: guaB PubMed

• Expression browser: guaB PubMed

• Sigma factor:

• Regulation:
  • activated during growth in the presence of branched chain amino acids (CodY) PubMed

• Regulatory mechanism:
  • CodY: transcription activation PubMed

• Additional information:
  • the mRNA is very stable (half-life > 15 min) PubMed
  • inhibition of enzymatic activity by (p)ppGpp during the ´stringent response´PubMed
  • belongs to the 100 most abundant proteins PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 3210 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 20338 PubMed

Biological materials

• Mutant:

• Expression vector:
  • purification from B. subtilis with an N-terminal Strep-tag, for SPINE, (in pGP380): pGP901, available in Stülke lab

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody: