Sequence analysis of two deletion mutants in the hisC gene of Salmonella typhimurium

Limited sequencing of the terminal region of the hisC gene in two deletion mutants involving the hisC gene of Salmonella typhimurium was carried out after polymerase chain reaction amplification of the appropriate region, using oligonucleotide primers selected from the published sequence of the histidine operon from this organism. his2648 was shown to have a 34 base pair deletion in the terminal region of the hisC gene between the P2 promoter and the Shine-Delgarno sequence of the hisB gene. hisHB22 was shown to have a 1.4 kilobase deletion extending from the TGA termination codon of the hisC gene to the middle of the hisH gene. The sequence data were consistent with previous genetic and phenotypic characterization of these strains.