Functional homology between E. coli ribosomal protein L11 and B. megaterium protein BM-L11

Summary Ribosomes from the thiostrepton-resistant mutant MJ1 of Bacillus megaterium completely lack a protein designated BM-L11. When assayed in vitro, such ribosomes show an impaired ability to hydrolyse GTP in the presence of the elongation factor EF-G and are unable to support the synthesis of (p)ppGpp in response to the stringent factor. Restoration of both these activities can be achieved by re-addition of either protein BM-L11 or its serological homologue from Escherichia coli, protein L11, implying that these two proteins are related functionally as well as immunologically.