AlkylationAlkylating AgentsMethyl MethanesulfonateDNA DamageDNA RepairMethylnitronitrosoguanidineO(6)-Methylguanine-DNA MethyltransferaseMonomethylhydrazineDNA GlycosylasesDNA Repair EnzymesN-Glycosyl HydrolasesMethylnitrosoureaMutagensEndodeoxyribonucleasesMethyltransferasesMutationEscherichia coliDNAEscherichia coli ProteinsGuanineUltraviolet RaysPalladiumDNA Mismatch RepairNitrogen Mustard CompoundsStereoisomerismDNA-Binding ProteinsDNA AdductsAllyl CompoundsDNA Breaks, Double-StrandedEthylnitrosoureaComet AssayIodoacetamideEthylmaleimideMolecular StructureIodoacetatesMolecular Sequence DataCysteine