Fluorescent single-stranded DNA-binding proteins enable in vitro and in vivo studies.

Fluorescent single-stranded DNA-binding proteins (SSB) that have a defined number of fluorophores per tetramer are invaluable tools to understand biochemical mechanism and biological function. Here, we describe the purification of fluorescent SSB chimeras with a unique number of fluorescent subunits incorporated per tetramer. We describe the use of these tetramers to enable clear visualization of SSB in vivo. Purified chimeras also facilitate single molecule studies (Liu et al., Protein Sci 20:1005-1020, 2011).