A restriction enzyme cleavage map of the histidine utilization ( hut ) genes of Klebsiella aerogenes and deletions lacking regions of hut DNA

Abstract

The histidine utilization ( hut ) operons of Klebsiella aerogenes were cloned into pBR322. The hut genes are wholly contained on a 7.9 kilobase pair fragment bounded by Hin dIII restriction sites and expression of hut is independent of the orientation of the fragment with respect to pBR322. A restriction map locating the 27 cleavage sites within hut for the enzymes, Hin dIII, Pvu II, Sal I, Bgl II, Kpn I, Pst I, Sma I, Ava I, and Bam HI was deduced. Several of the cleavage sites for the enzymes Hae III and Hin fI were also mapped. A set of deletion plasmids was isolated by removing various restriction fragments from the original plasmid. These deletions were characterized and were used to assist in mapping restriction sites. This physical characterization of hut DNA opens the way for genetic and molecular analysis of the regulation of hut gene expression in vitro as well as in vivo.