1. (a) Microorganisms can be used to remove chemical pollutants from the environment. ine gene cluster...
1. (a) Microorganisms can be used to remove chemical pollutants from the environment. ine gene cluster xyl encodes several enzymes that are involved in degrading toluene, and transcription of these genes is activated when the xylS protein (expressed continuously under a constitutively active promoter p) binds to toluene. Only then can the resulting xyls/toluene complex bind to the pm promoter to activate transcription of the genes in the xyl cluster. By considering the cellular location of the enzymes that degrade toluene, identify a potential problem in using whole bacterial cells to remove this pollutant from the environment. (1 point) (b) Dimethyl sulfate (CH3OS02OCH3) is a reagent for introducing random mutations into genes. It works by reacting with guanine nucleobases to give MeOⓇG (shown below), which pairs with thymidine (T) rather than cytidine (C). Draw structures for the MeOⓇG:T and MeO®G:C nucleobase pairs and hence explain why the presence of MeO®G leads to a mutation in the gene during DNA replication. (3 points) OCH3 レース DNA МеобG