Escherichia coli ribosomal protein L10 is rapidly degraded when synthesized in excess of ribosomal protein L7/L12.

AUTOR(ES)

Petersen, C

RESUMO

In Escherichia coli the genes encoding ribosomal proteins L10 and L7/12, rplJ and rplL, respectively, are cotranscribed and subject to translational coupling. Synthesis of both proteins is coordinately regulated at the translational level by binding of L10 or a complex of L10 and L7/L12 to a single target in the mRNA leader region upstream of rplJ. Unexpectedly, small deletions that inactivated the ribosome-binding site of the rplL gene carried on multicopy plasmids exerted a negative effect on expression of the upstream rplJ gene. This effect could be overcome by overproduction of L7/L12 in trans from another plasmid. This apparent stimulation resulted from stabilization of the overproduced L10 protein by L7/L12, presumably because free L10, in contrast to L10 complexed with L7/L12, is subject to rapid proteolytic decay. The contribution of this decay mechanism to the regulation of the rplJL operon is evaluated.

Documentos Relacionados

• Autogenous control of Escherichia coli ribosomal protein L10 synthesis in vitro.
• Guanosinetriphosphatase activity dependent on elongation factor Tu and ribosomal protein L7/L12.
• A single-headed dimer of Escherichia coli ribosomal protein L7/L12 supports protein synthesis
• Determination of the promoter strength in the mixed transcription system: promoters of lactose, tryptophan and ribosomal protein L10 operons from Escherichia coli.
• Characterization of the L11, L1, L10 and L12 equivalent ribosomal protein gene cluster of the halophilic archaebacterium Halobacterium cutirubrum.