Use of PCR to isolate genes encoding σ⁵⁴-dependent activators from diverse bacteria

Degenerate PCR probes were used to amplify gene fragments encoding the catalytic domain of σ⁵⁴-dependent transcription activators. The procedure should be widely applicable, as it recovered both known and novel gene fragments: 5 from Rhizobium meliloti, 13 from Myxococcus xanthus, and 3 from Bacillus subtilis. No fragments were obtained from Synechococcus sp. strain PCC 7002 or Saccharomyces cerevisiae.