PHOTOREVERSIBILITY OF INDUCED MUTATIONS IN A NONPHOTOREACTIVABLE STRAIN OF ESCHERICHIA COLI

Abstract
A radiation-resistant derivative (strain H/r) of the nonphotoreactivable mutant strain isolated by Harm was found to be incapable of photoreversing UV-induced mutations to streptonycin resistance, as well as UV killing. Photoreversibility of UV-induced mutations to prototrophy, however, was found to be essentially normal in an agrinine-requiringsubstrain of H/r (H/r30). It was concluded that photoreversal of UV -induced mutations to prototrophy does not require the "photoreactiv-ating enzyme.".