Structure of the single-stranded DNA-binding protein SSB from Thermus aquaticus

The crystal structure of the single-stranded DNA-binding protein from Thermus aquaticus has been solved and refined at 1.85 angstrom resolution. Two monomers, each encompassing two oligonucleotide/oligosaccharide-binding (OB) domains and a number of flexible beta-hairpin loops, form an oligomer of approximate D-2 symmetry typical of bacterial SSBs. Comparison with other SSB structures confirms considerable variability in the mode of oligomerization and aggregation of SSB oligomers.