LexA

• Description: transcriptional repressor of the SOS regulon
  
  

Gene name	lexA
Synonyms	dinR
Essential	no
Product	transcriptional repressor of the SOS regulon
Function	regulation of DNA damage repair
MW, pI	22 kDa, 5.155
Gene length, protein length	615 bp, 205 aa
Immediate neighbours	fosB, yneA
Get the DNA and protein sequences (Barbe et al., 2009)
Genetic context This image was kindly provided by SubtiList

The gene

Basic information

• Locus tag: BSU17850

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: Represses dinA, dinB, dinC, recA genes and itself by binding to the 14 bp palindromic sequence 5'-CGAACNNNNGTTCG-3'. In the presence of single-stranded DNA, RecA interacts with LexA causing an autocatalytic cleavage which disrupts the DNA-binding part of LexA, leading to derepression of the SOS regulon and eventually DNA repair. (according to Swiss-Prot)

• Protein family: peptidase S24 family (according to Swiss-Prot)

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions:

• Localization:

Database entries

• Structure:

• Swiss prot entry: P31080

• KEGG entry: [3]

• E.C. number:

Expression and regulation

• Operon: lexA

• Sigma factor: sigB PubMed

• Regulation: autoregulation by LexA PubMed
  • repressed when no DNA damage is present (LexA) PubMed

• Regulatory mechanism: autorepression
  • LexA: transcription repression PubMed

• Additional information:

Biological materials

• Mutant:

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

References

B J Haijema, D van Sinderen, K Winterling, J Kooistra, G Venema, L W Hamoen
Regulated expression of the dinR and recA genes during competence development and SOS induction in Bacillus subtilis.
Mol Microbiol: 1996, 22(1);75-85
[PubMed:8899710] [WorldCat.org] [DOI] (P p)