Regulation and Function of Cellular Gene Products Involved in UV and Chemical Mutagenesis in E . Coli

The past few years have seen a remarkable increase in our understanding of the strategies employed by cells in dealing with damage to their genetic material. Of particular interest has been the recognition that mutagenesis by a variety of agents including UV, methyl methanesulfonate (MMS), and 4-nitroquinoline-1-oxide (NQO) is not a passive process. Rather it requires the intervention of a cellular system which processes damaged DNA in such a way that mutations result. Mutagenesis is not a necessary consequence of DNA damage since, if this system is inactivated, no mutations result. In this paper we would like to summarize some of the recent work of our lab on the cellular molecular mechanisms involved in UV and chemical mutagenesis.