The nucleotide sequence of a 6,000 bp region of the E. coli chromosome that includes the 3' end of the coding region for the thyA gene and the entire recC gene has been determined. The proposed coding region for the RecC protein is 3369 nucleotides long, which would encode a polypeptide consisting of 1122 amino acids with a calculated molecular mass of 129 kDa. Mung bean nuclease mapping of a recC specific transcript produced in vivo indicates that transcription of recC is initiated 80 bp upstream of the translational start point. A weak promoter sequence situated 5' to the transcription initiation point has been identified. In the 1953 bp thyA-recC intergenic region there are three open reading frames that would code for polypeptides of molecular mass 30 kDa, 13.5 kDa and 12 kDa, respectively. Although the first and third of these open reading frames are preceded by possible ribosome binding sites, no obvious promoter sequences could be identified. Moreover, transcripts for these reading frames could not be detected.