Photoreversal and “dark repair” of mutations to prototrophy induced by ultraviolet light in photoreactivable and non-photoreactivable strains of Escherichia coli
EM Witkin - … Research/Fundamental and Molecular Mechanisms of …, 1964 - Elsevier
A photoreactivable variant (strain H r 30-R), obtained from a radiation-resistant, argenine-
requiring derivative (strain H r 30) of Harm's non-photoreactivable (phr−) mutants of
Escherichia coli B, is compared with its parent strain. The photoreversibility of UV-induced
mutations to prototrophy is found to be about the same in the two strains. Since the phr−
strain lacks the ability to split thymine dimers produced by UV in its DNA, but photreverses
these mutations to the same extent as does the phr+ strain, it is concluded that the UV …
requiring derivative (strain H r 30) of Harm's non-photoreactivable (phr−) mutants of
Escherichia coli B, is compared with its parent strain. The photoreversibility of UV-induced
mutations to prototrophy is found to be about the same in the two strains. Since the phr−
strain lacks the ability to split thymine dimers produced by UV in its DNA, but photreverses
these mutations to the same extent as does the phr+ strain, it is concluded that the UV …
