ssbA [2018-03-08 18:41:40]

single-strand DNA-binding protein, part of the [SW|replisome], promoter of [protein|search|RecA ]DNA repair center assembly, required to internalize and to recombine ssDNA with homologous resident duplex

locus: BSU40900

pI: 4.82

mw: 18.60 kDa

protein length: 172 aa

gene length: 516 bp

function: [category|SW 3.1.1|DNA replication], [category|SW 3.1.5|DNA repair/ recombination]

product: single-strand DNA-binding protein

essential: yes

synonyms: ssb

Genomic Context

categories

• [category|SW 3|Information processing] → [category|SW 3.1|Genetics] → [category|SW 3.1.1|DNA replication]
• [category|SW 3|Information processing] → [category|SW 3.1|Genetics] → [category|SW 3.1.5|DNA repair/ recombination]
• [category|SW 3|Information processing] → [category|SW 3.1|Genetics] → [category|SW 3.1.5|DNA repair/ recombination] → [category|SW 3.1.5.6|Other proteins]
• [category|SW 6|Groups of genes] → [category|SW 6.1|Essential genes]
• [category|SW 6|Groups of genes] → [category|SW 6.4|Phosphoproteins] → [category|SW 6.4.1|Phosphorylation on an Arg residue]
• [category|SW 6|Groups of genes] → [category|SW 6.4|Phosphoproteins] → [category|SW 6.4.7|Phosphorylation on a Tyr residue]

Gene

Coordinates: 4,198,886 → 4,199,404

Phenotypes of a mutant

• essential [Pubmed|12682299]

The protein

Catalyzed reaction/ biological activity

• SsbA inhibits ssDNA phosphorylase activity of [protein|64C6D783FF3F41C81B216F798A1DC8071345B1ED|PnpA] [Pubmed|21859751]
• SsbA co-assembles onto [protein|1CDF658441061EA476E27C2E60DEE45C4F45AC15|SsbB]-coated ssDNA [Pubmed|22373918]
• important for [protein|A44D4677FB70BE8F554BF1001A500F817C7DA95F|RecA] DNA repair center assembly by recruiting [protein|80E6F156764FF30300D034EE6FB44F2DB8338AF3|RecO] and [protein|BEBAF1EB53EBB3E7558BB5FE73C418B50000FA29|RecR] to the [SW|replisome] [Pubmed|24891441]
• RecA-ATP in concert with [protein|FC53216F600994C862F0C0D017C3FA28EB75DCB6|DprA] and [protein|8DE39680CA7663803A107066FBE9AFFCC77DB72A|SsbA] catalyzes DNA strand exchange, with [protein|1CDF658441061EA476E27C2E60DEE45C4F45AC15|SsbB] as an accessory factor [Pubmed|25138221]

Paralogous protein(s)

• [protein|1CDF658441061EA476E27C2E60DEE45C4F45AC15|SsbB]

Modification

• phosphorylated on Arg-76 [Pubmed|22517742]
• phosphorylated on Tyr-82 by [protein|6100EA37592A2C31BC3DE79AD7948A8D6F65F6E1|PtkA], dephosphorylated by [protein|CF73D86DB024575BE8F043A4C3996458F4262E46|PtpZ] [Pubmed|16549871]

Effectors of protein activity

• Phosphorylation of Ssb increases binding to single-stranded DNA in vitro almost 200-fold [Pubmed|16549871]

Structure

• [PDB|3VDY] (SsbB in complex with ssDNA, 63% identity, 87% similarity) [Pubmed|22373918]

[SW|Localization]

• forms foci [Pubmed|21958350]
• Nucleoid (Mid-cell) [Pubmed|16479537]

Expression and Regulation

Operons

• genes: [gene|BD162A17E5F3F9AB49E478CE72D0FE92D82E6673|yyzM]-[gene|FEE1952DFA3D6A5E2DC108B3B203B526642E2C68|yyaE]-[gene|C0F5FAD6DF89DA9E0FFC8F888D7CED6AA42D9C73|yyaF]-[gene|9D25B8F4579C41E77AE9CDD18CAD6DA37F3DD0A2|rpsF]-[gene|8DE39680CA7663803A107066FBE9AFFCC77DB72A|ssbA]-[gene|C0B926F1134A7A3FEEC886F9AF67F694C8E0C089|rpsR]
  description: [Pubmed|22383849]

• genes: [gene|C0F5FAD6DF89DA9E0FFC8F888D7CED6AA42D9C73|yyaF]-[gene|9D25B8F4579C41E77AE9CDD18CAD6DA37F3DD0A2|rpsF]-[gene|8DE39680CA7663803A107066FBE9AFFCC77DB72A|ssbA]-[gene|C0B926F1134A7A3FEEC886F9AF67F694C8E0C089|rpsR]
  description: [Pubmed|14762004]

  sigma factors

  • [protein|360F48D576DE950DF79C1A2677B7A35A8D8CC30C|SigA]: sigma factor, [Pubmed|24310371], in [regulon|360F48D576DE950DF79C1A2677B7A35A8D8CC30C|SigA regulon]

  regulatory mechanism

  • [protein|08CFA2C72931A75532D4289BC1D18A826DE9F9CA|ComK]: activation, in [regulon|08CFA2C72931A75532D4289BC1D18A826DE9F9CA|ComK regulon]
  • [regulon|stringent response|stringent response]: negative regulation, in [regulon|stringent response|stringent response]

  regulation

  • [protein|search|ComK]: transcription activation [Pubmed|11948146]

• genes: [gene|9D25B8F4579C41E77AE9CDD18CAD6DA37F3DD0A2|rpsF]-[gene|8DE39680CA7663803A107066FBE9AFFCC77DB72A|ssbA]-[gene|C0B926F1134A7A3FEEC886F9AF67F694C8E0C089|rpsR]
  description: [Pubmed|24310371,22383849]

  regulation

  • [protein|search|ComK]: transcription activation [Pubmed|11948146]

Biological materials

two-hybrid system

• ''B. pertussis'' adenylate cyclase-based bacterial two hybrid system ([SW|BACTH]), available in [SW|Fabian Commichau]'s lab

References

Reviews

• 22976189,22933559

Original publications

• 17853894,19730681,11948146,16479537,11948165,16549871,20122408,14762004,20581116,22054219,22373918,22517742,21859751,21170359,21958350,23268446,23536821,23779106,22383849,24310371,24443534,24891441,25138221,26707201,26786319,28575448,28878042,29059392,29059328