Publication Abstract from PubMed
In Escherichia coli, 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. The structure of the enzyme has previously been determined in a hexagonal space group at 2.4 A resolution. Here, the structure of ExoI in complex with a nucleotide product, thymidine 5'-monophosphate, is described in an orthorhombic space group at 1.5 A resolution. This new high-resolution structure provides some insight into the interactions involved in binding a nucleotide product. The conserved active site contains a unique metal-binding position when compared with orthologous sites in the Klenow fragment, T4 DNA polymerase and dnaQ. This unique difference is proposed to be a consequence of the repositioning of an important histidine, His181, away from the active site.
Structure of Escherichia coli exonuclease I in complex with thymidine 5'-monophosphate.,Busam RD Acta Crystallogr D Biol Crystallogr. 2008 Feb;64(Pt 2):206-10. Epub 2008, Jan 16. PMID:18219121[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
