COMPLEMENTATION OF THE PROTEIN-TRANSPORT DEFECT OF AN ESCHERICHIA-COLI SEC-Y MUTANT (SECY24) BY BACILLUS-SUBTILIS-SEC-Y HOMOLOG

Bacillus subtilis SecY homologue shares 41.3% homology with that of E. coli and remarkably higher homologous regions (more than 80%) are present in the four cytoplasmic regions [(1990) J. Biochem. 107, 603-607]. Based on the formation of the mature form of OmpA in E. coli, we have shown that the protein transport defect of the E. coli sec Y mutant (secY24) is complemented by the gene product from the B. subtilis sec Y homologue, which is expressed under the lac promoter control. However, B. subtilis SecY could not restore growth of the E. coli mutant at non-permissive temperature. © 1990.