What is the name of the single-stranded DNA binding protein in eukaryotes?

The single-stranded DNA-binding protein in eukaryotes is replication protein A, usually abbreviated RPA. It binds exposed single-stranded DNA during replication, recombination, and several DNA-repair pathways.

RPA protects unwound DNA from folding into troublesome secondary structures and from being degraded by nucleases. During replication, helicase separates the two DNA strands, and RPA coats the resulting single-stranded regions so primase and polymerases can work on a stable template. RPA also helps recruit and organize proteins involved in damage recognition and repair.

In most eukaryotes, RPA is a heterotrimer composed of RPA1, RPA2, and RPA3. These subunits contain oligonucleotide/oligosaccharide-binding folds that contact single-stranded DNA. The bacterial counterpart is generally called SSB, or single-strand binding protein; RecA is instead a recombination protein, while DnaB is a helicase. Thus, SSB is a reasonable bacterial answer but not the canonical eukaryotic one.