Suppressibility of recA, recB, and recC mutations by nonsense suppressors.

Mutations in the recA, recB, and recC genes of Escherichia coli K-12 were surveyed to ascertain whether or not they are suppressed by nonsense suppressors. Several mutations which map in or near the recA gene, but have not been called recA mutations, were also surveyed. An amber recB mutation, recB156, and an amber recC mutation, recC155, were isolated. One recB mutation, recB95, and four recC mutations, recC22, recC38, recC82, and recC83, were found to be suppressed by a UGA suppressor. In addition to the previously isolated amber recA mutation recA99, two other recA mutations, recA52 and recA123, were found to be suppressed by amber suppressor supD32 but not by supE44.