Abstract
Single-stranded DNA binding proteins (SSBs) play central roles in cellular and viral processes involving the:generation of single-stranded DNA, These include DNA replication, homologous recombination and DNA repair pathways. SSBs bind DNA using four 'OB-fold' (oligonucleotide/oligosaccharide binding fold) domains that can be organised in a variety of overall quaternary structures. Thus eubacterial SSBs are homotetrameric whilst the eucaryal RPA protein is a-heterotrimer and euryarchaeal proteins vary significantly in their subunit compositions, We demonstrate that the crenarchaeal SSB protein is an abundant protein with a unique structural organisation, existing as a monomer in solution and multimerising on DNA binding. The protein binds single-stranded DMA distributively with a binding site size of similar to5 nt per monomer, Sulfolobus SSB lacks the zinc finger motif found in the eucaryal and euryarchaeal proteins, possessing instead a flexible C-terminal tail, sensitive to trypsin digestion, that is not required for DNA binding, In comparison with Escherichia coli SSB, the tail may play a role in protein-protein interactions during DNA replication and repair.
Original language | English |
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Volume | 29 |
Publication status | Published - 15 Feb 2001 |
Keywords
- NUCLEOTIDE EXCISION-REPAIR
- REPLICATION PROTEIN
- ESCHERICHIA-COLI
- CRYSTAL-STRUCTURE
- EXONUCLEASE-I
- RAD52 PROTEIN
- SSB
- RPA
- COMPLEXES
- DOMAIN