This entry represents the ExoI SH3-like domain found in bacterial exonuclease I. In bacteria, exonuclease I (ExoI) is a monomeric processive 3'-5' exonuclease that degrades single-stranded DNA. The enzyme has been implicated as primarily being involv ...
This entry represents the ExoI SH3-like domain found in bacterial exonuclease I. In bacteria, exonuclease I (ExoI) is a monomeric processive 3'-5' exonuclease that degrades single-stranded DNA. The enzyme has been implicated as primarily being involved in repairing frameshift mutations. ExoI consists of three domains: an N-terminal nuclease domain (Pfam:PF00929) with homology to the proofreading domain of E. coli DNA polymerase I and other DnaQ superfamily enzymes, a central domain with a portion that resembles an SH3 domain fold and a C- terminal alpha-helical domain (Pfam:PF26016). While a typical SH3-like domain consists of five or six antiparallel beta-strands that form a compact beta-sandwich, the beta-sandwich of the SH3-like domain in ExoI is surrounded by alpha-helices, resulting in a substantially elaborated fold [2-4].