DNA-Unwinding Dynamics of Escherichia coli UvrD Lacking the C-Terminal 40 Amino Acids (Biophysical Journal)

The E. coli UvrD protein is a nonhexameric DNA helicase that belongs to superfamily I and plays a crucial role in both nucleotide excision repair and methyl-directed mismatch repair. Previous data suggested that wild-type UvrD has optimal activity in its oligomeric form. However, crystal structures of the UvrD-DNA complex were only resolved for monomeric UvrD, using a UvrD mutant lacking the C-terminal 40 amino acids (UvrD?40C). However, biochemical findings performed using UvrD?40C indicated that this mutant failed to dimerize, although its DNA-unwinding activity was comparable to that of wild-type UvrD.