The crystal structure of Thermus aquaticus single-stranded DNA binding protein (SSB) and in particular of one of its flexible regions was elucidated using high-multiplicity data collected on an X8 PROTEUM diffraction system. Highquality X8 PROTEUM data allowed the refinement of two conformations of the glycine rich C-terminal region that previously were not traceable from electron density maps obtained from synchrotron data.

Protein and Crystal Data

Bacterial single-stranded DNA-binding (SSB) proteins play an important role in DNA metabolism. They protect the vulnerable single-stranded DNA (ssDNA) from nucleolytic digestion and prevent hairpin formation, thus keeping ssDNA in a suitable conformation during DNA replication, repair and recombination. Moreover the presence of SSB proteins is essential for the survival of bacteria and they are believed to belong to the minimal set of genes required for cellular life.