Human single-stranded DNA binding protein 1 (hSSB1, OBFC2B), a critical component of the DNA damage response

Abstract

Our genomic DNA is found predominantly in a double-stranded helical conformation. However, there are a number of cellular transactions and DNA damage events that result in the exposure of single stranded regions of DNA. DNA transactions require these regions of single stranded DNA, but they are only transient in nature as they are particularly susceptible to further damage through chemical and enzymatic degradation, metabolic activation, and formation of secondary structures. To protect these exposed regions of single stranded DNA, all living organisms have members of the Single Stranded DNA Binding (SSB) protein family, which are characterised by a conserved oligonucleotide/oligosaccharide-binding (OB) domain. In humans, three such proteins members have been identified; namely the Replication Protein A (RPA) complex, hSSB1 and hSSB2. While RPA is extremely well characterised, the roles of hSSB1 and hSSB2 have only emerged recently. In this review, we discuss the critical roles that hSSB1 plays in the maintenance of genomic stability.