New chromosomal location for structural genes of ribosomal proteins

Abstract

An Escherichia coli mutant, ts9, previously reported to have an electrophoretically altered ribosomal protein, has been further characterized and the altered component has been identified as L7/L12. Although mutant ts9 is temperature sensitive for growth (rts -), the rts and L7/L12 mutations are genetically separable and are both located between argH and rif. The L7/L12 mutation (rpyL) maps very close to relC, mutants of which have a defect in the 50S ribosomal subunit. The gene order is argH rts (rpyL, relC) rif. Protein synthesis directed by bacteriophage λc1857S7drif(d)18 in ultraviolet irradiated cells indicates that L7/L12, as well as L1, L10, L11, and possibly L8 or L9 are coded by the phage DNA. Results obtained indicate that rpyL is the structural gene for L7/L12 and that this region of the E. coli chromosome contains a cluster of structural genes for ribosomal proteins.