SsbA

• Description: single-strand DNA-binding protein, part of the replisome, promoter of RecA DNA repair center assembly
  
  

Gene name	ssbA
Synonyms	ssb
Essential	yes PubMed
Product	single-strand DNA-binding protein
Function	DNA replication, DNA repair/ recombination
Gene expression levels in SubtiExpress: ssbA
Interactions involving this protein in SubtInteract: SsbA
MW, pI	18 kDa, 4.822
Gene length, protein length	516 bp, 172 aa
Immediate neighbours	rpsR, rpsF
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

DNA replication, DNA repair/ recombination, essential genes, phosphoproteins

This gene is a member of the following regulons

ComK regulon, stringent response

The gene

Basic information

• Locus tag: BSU40900

Phenotypes of a mutant

essential PubMed

Database entries

• BsubCyc: BSU40900

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity:
  • SsbA inhibits ssDNA phosphorylase activity of PnpA PubMed
  • SsbA co-assembles onto SsbB-coated ssDNA PubMed
  • important for RecA DNA repair center assembly by recruiting RecO and RecR to the replisome PubMed

• Protein family:

• Paralogous protein(s): SsbB

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:
  • phosphorylated on Arg-76 PubMed
  • phosphorylated on Tyr-82 by PtkA, dephosphorylated by PtpZ PubMed

• Cofactors:

• Effectors of protein activity: Phosphorylation of Ssb increases binding to single-stranded DNA in vitro almost 200-fold PubMed

• Interactions:
  • forms tetramers PubMed
  • part of the replisome: PolC-HolA-HolB-DnaX-DnaN-DnaG-DnaC-DnaI-DnaD-SsbA-DnaE-PriA-DnaB PubMed
  • SsbA-SbcC PubMed
  • SsbA-RecG PubMed
  • SsbA-YrvE PubMed
  • SsbA-YrvN PubMed
  • SsbA (bound to ssDNA) -RecO, this helps to dislodge SsbA and SsbB from ssDNA PubMed
  • SsbA-YqiB PubMed
  • SsbA-Ung PubMed
  • SsbA-YpbB PubMed
  • SsbA-RecD2 PubMed
  • SsbA-DnaN PubMed
  • SsbA (bound to ssDNA) -RecO, this helps to dislodge SsbA and SsbB from ssDNA PubMed
  • SsbA-YocI according to PubMed
  • SsbA-RecQ according to PubMed

• Localization:
  • forms foci PubMed
  • Nucleoid (Mid-cell) PubMed

Database entries

• BsubCyc: BSU40900

• Structure: 3VDY 3VDY (SsbB in complex with ssDNA, 63% identity, 87% similarity) PubMed

• UniProt: P37455

• KEGG entry: [3]

• E.C. number:

Expression and regulation

• Operon:
  • yyaF-rpsF-ssbA-rpsR PubMed
  • rpsF-ssbA-rpsR PubMed

• Expression browser: ssbA PubMed

• Sigma factor:
  • rpsF: SigA PubMed

• Regulation:
  • RelA dependent downregulation (Class I) during stringent response PubMed
  • ComK: transcription activation PubMed

• Additional information:
  • the mRNA contains a structured motif in the 5' UTR upstream of the rpsF ORF that is bound by RpsF-RpsR heterodimers and may be implicated in autogenous regulation PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 279 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 2199 PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium, exponential phase): 263 PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium, early stationary phase after glucose exhaustion): 147 PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium, late stationary phase after glucose exhaustion): 3701 PubMed

Biological materials

• Mutant:

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

References

Reviews

Dusica Vujaklija, Boris Macek
Detecting posttranslational modifications of bacterial SSB proteins.
Methods Mol Biol: 2012, 922;205-18
[PubMed:22976189] [WorldCat.org] [DOI] (I p)

Justin S Lenhart, Jeremy W Schroeder, Brian W Walsh, Lyle A Simmons
DNA repair and genome maintenance in Bacillus subtilis.
Microbiol Mol Biol Rev: 2012, 76(3);530-64
[PubMed:22933559] [WorldCat.org] [DOI] (I p)