Mechanistic studies on DNA photolyase, II. Is the blue enzyme isolated from Escherichia coli a mutant?

The contrasting properties of the DNA photolyases isolated from Escherichia coli, and from Saccharomyces cerevisiae suggested the possibility that the E. coli enzyme may have suffered mutagenesis as a consequence of the extensive use of ultraviolet irradiation/photoreactivation as a selection technique during the cloning. We have therefore recloned this gene using a UV-independent protocol and confirmed the original sequence.