The Escherichia coli histone-like protein HU has a role in stationary phase adaptive mutation.
Stationary phase adaptive mutation in Escherichia coli is thought to be a mechanism by which mutation rates are increased during stressful conditions, increasing the possibility that fitness-enhancing mutations arise. Here we present data showing that the histone-like protein, HU, has a role in the molecular pathway by which adaptive Lac(+) mutants arise in E. coli strain FC40. Adaptive Lac(+) mutations are largely but not entirely due to error-prone DNA polymerase IV (Pol IV). Mutations in either of the HU subunits, HUalpha or HUbeta, decrease adaptive mutation to Lac(+) by both Pol IV-dependent and Pol IV-independent pathways. Additionally, HU mutations inhibit growth-dependent mutations without a reduction in the level of Pol IV. These effects of HU mutations on adaptive mutation and on growth-dependent mutations reveal novel functions for HU in mutagenesis.
Williams
Ashley B
AB
Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
Foster
Patricia L
PL
D000222:Adaptation, Physiological / Q000235:genetics*; D019951:DNA Polymerase beta; D004268:DNA-Binding Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D007763:Lac Operon; D009154:Mutation / Q000502:physiology*; D021122:Protein Subunits / Q000235:genetics
D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D021122:Protein Subunits; C116822:hns protein, E coli; D019951:DNA Polymerase beta