ABSTRACT

Homologous recombination (HR) is an essential process used to repair both programmed and accidental DNA double-strand breaks (DSBs). Single-strand binding proteins 1 and 2 (SSB1 and SSB2) play a critical role in HR. Although the exact mechanism of these SSBs is not fully understood, studies have shown that depletion of these proteins can lead to inefficient HR and genomic instability. Here we present evidence that SSB1 and SSB2 share similar functions, homology, secondary structures, and tertiary structures. Furthermore, we have found evidence that two pairs of residues in these SSBs show similar patterns of mutations. Through a CLUSTAL multiple sequence alignment, we found that mutations in SSB1 had the same mutations in the corresponding amino acids in SSB2. Using the same method, we also found that SSB1 had different mutations in corresponding amino acids found in SSB2. This suggests that these sites of interest could potentially be essential to the SSB functions and help us to characterize the role that these SSBs play in HR.