substantial extent of proteolytic cleavage
partial reduction in UV mutability
the site-directed mutation of UmuDAb at Ala83 abolishes cleavage activity
reduced ability to for a heterodimer with UmuD'
ability to participate in UV mutagenesis and RecA-mediated cleavage are similar to that of the wild-type enzyme
site-directed mutagenesis, that removes the cleavage site Cys residue of UmuD, the mutation does not substantially affect UmuD function, cleavage site variant
poor extent of proteolytic cleavage
site-directed mutagenesis, that removes the cleavage site Cys residue of UmuD, the mutation does not substantially affect UmuD function, cleavage site variant. For cleavage to occur, UmuD UmuD G25D dimer must first exchange in the presence of RecA:ssDNA, and any cleavage detected results from cleavage in trans. Cleavage is less efficient in this context, indicating that the decreased rate of cleavage in the trans dimers results from the time required for dimer exchange to first take place before cleavage can occur
reduced ability to form a homodimer and a heterodimer with UmuD'