[Regulation of the activity of the Escherichia coli K-12 uridine phosphorylase gene. I. Mapping of the structural gene mutations and a determination of the direction of transcription].

A fine genetic mapping of some point and deletion mutations for uridine phosphorylase (udp) gene, including deletions covering simultaneously the udp and the adjacent metE gene was carried out. Deletions of the latter type do not recombine with the udp promoter mutations isolated previously (Mironov, Sukhodolets 1979) thus suggesting that the udp promoter is situated at the site adjoining metE.