Temporal constraints on the incorporation of regulatory mutants in evolutionary pathways.

ABSTRACT: Understanding the molecular details of the sequence of events in multistep evolutionary pathways can reveal the extent to which natural selection exploits regulatory mutations affecting expression, amino acid replacements affecting the active site, amino acid replacements affecting protein folding or stability, or variations affecting gene copy number. In experimentally exploring the adaptive landscape of the evolution of resistance to beta-lactam antibiotics in enteric bacteria, we noted that a regulatory mutation that increases beta-lactamase expression by about 2-fold has a very strong tendency to be fixed at or near the end of the evolutionary pathway. This pattern contrasts with previous experiments selecting for the utilization of novel substrates, in which regulatory mutations that

SUBMITTER: Brown KM 

PROVIDER: S-EPMC2912465 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature