CysK

• Description: trigger enzyme: cysteine synthetase A and control of CymR activity
  
  

Gene name	cysK
Synonyms
Essential	no
Product	trigger enzyme: cysteine synthetase A
Function	biosynthesis of cysteine, control of CymR activity
Gene expression levels in SubtiExpress: cysK
Interactions involving this protein in SubtInteract: CysK
Metabolic function and regulation of this protein in SubtiPathways: cysK
MW, pI	32 kDa, 5.492
Gene length, protein length	924 bp, 308 aa
Immediate neighbours	yacD, pabB
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 amino acids, transcription factors and their control, trigger enzyme, most abundant proteins

This gene is a member of the following regulons

CymR regulon, Spx regulon

The gene

Basic information

• Locus tag: BSU00730

Phenotypes of a mutant

constitutive expression of the cysH-cysP-sat-cysC-ylnD-ylnE-ylnF operon, auxotrophic for cysteine

Database entries

• BsubCyc: BSU00730

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: O(3)-acetyl-L-serine + H₂S = L-cysteine + acetate (according to Swiss-Prot)

• Protein family: cysteine synthase/cystathionine beta-synthase family (according to Swiss-Prot)

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactors:

• Effectors of protein activity:

• Interactions:
  • CymR-CysK, the complex is formed in the presence of cysteine, and results in DNA binding and repression of genes of cysteine biosynthesis PubMed

• Localization:

Database entries

• BsubCyc: BSU00730

• Structure: 1Y7L (from Haemophilus influenzae, 39% identity, 52% similarity) PubMed

• UniProt: P37887

• KEGG entry: [3]

• E.C. number: 2.5.1.47

Expression and regulation

• Operon: cysK PubMed

• Expression browser: cysK PubMed

• Sigma factor: SigA PubMed

• Regulation:
  • repressed by casamino acids PubMed
  • repressed in the presence of cysteine (CymR) PubMed

• Regulatory mechanism:
  • CymR: transcription repression PubMed
  • Spx: transcription activation PubMed

• Additional information:
  • belongs to the 100 most abundant proteins PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 2939 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 10887 PubMed

Biological materials

• Mutant:
  • 1A834 ( cysK::kan), PubMed, available at BGSC
  • 1A801 ( cysK::spec), PubMed, available at BGSC
  • 1A803 ( cysK::spec), PubMed, available at BGSC
  • 1A946 ( cysK::spec), PubMed, available at BGSC

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

Labs working on this gene/protein

Isabelle Martin-Verstraete, Institute Pasteur, Paris, France