The evolution of new enzyme function: lessons from xenobiotic metabolizing bacteria versus insecticide-resistant insects

摘要: Here, we compare the evolutionary routes by which bacteria and insects have evolved enzymatic processes for degradation of four classes synthetic chemical insecticide. For insects, selective advantage such degradative activities is survival on exposure to insecticide, whereas simply a matter access additional sources nutrients. Nevertheless, highly efficient enzymes from wide variety enzyme families, relied upon generalist esterase-, cytochrome P450- glutathione-S-transferase-dependent detoxification systems. Moreover, mutant insect are less kinetically diverged in sequence their putative ancestors than bacterial counterparts. This presumably reflects several advantages that over acquisition new functions, as broad biochemical repertoire functions can be evolved, large population sizes, high effective mutation rates, very short generation times genetic diversity through horizontal gene transfer. Both systems support recent theory proposing often evolve ‘promiscuous’ existing enzymes, with subsequent mutations then enhancing those activities. Study will help resistance management, while potential bioremediants insecticide residues range contaminated environments.