Methylation Regulates the Expression of a DNA-modification Function Encoded by Bacteriophage Mu
This extract was created in the absence of an abstract.
Excerpt
Bacteriophage Mu encodes a DNA-modification function (Mom) which when expressed, renders its own as well as cellular DNA sequences, partially resistant to the action of several type-I restriction systems in vivo (Toussaint 1976) and to many of the known type-II restriction endonucleases in vitro (R. Kahmann and D. Kamp, in prep.). The latter feature has been exploited to determine the specificity of the modification. It was shown to occur at subsets of the sequence 5′ G/C-A-G/C-N-Py 3′ (R. Kahmann and D. Kamp, in prep.). The exact nature of the modification introduced by the Mom function has long been a mystery, especially since it was shown that the modified nucleotide is adenine but that the modification is not a methylation (Hattman 1979). Recent experiments by S. Hattman (pers. comm.) indicate that the modified adenine is N6-acetamidoadenine.
A variety of mutants defective in the mom gene have been isolated (Toussaint 1976; R....
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↵* Present address: Max-Planck-Institut für Molekulare Genetik, D-1000 Berlin 33, Federal Republic of Germany.
