Induction of ermC requires translation of the leader peptide.

AUTOR(ES)

Dubnau, D

RESUMO

ermC confers resistance to macrolide-lincosamide streptogramin B antibiotics by specifying a ribosomal RNA methylase, which results in decreased ribosomal affinity for these antibiotics. ermC expression is induced by exposure to erythromycin. We have previously proposed a translational regulation model in which erythromycin causes stalling of a ribosome, which is translating a leader peptide. Stalling causes a conformation shift in the ermC mRNA which in turn unmasks the methylase ribosomal binding site. A prediction of this translational attenuation model for ermC induction was tested by replacing the second codon of the putative ermC leader peptide coding region by TAA. As expected, the introduction of this mutation resulted in an uninducible phenotype which was suppressible by two ochre suppressor mutations in Bacillus subtilis. It is concluded that translation through the leader peptide coding region, in frame with the predicted leader peptide, is required for ermC induction.

Documentos Relacionados

• The ermC leader peptide: amino acid alterations leading to differential efficiency of induction by macrolide-lincosamide-streptogramin B antibiotics.
• Effect of ermC leader region mutations on induced mRNA stability.
• Conformational alterations in the ermC transcript in vivo during induction.
• Induction of ermC methylase in the absence of macrolide antibiotics and by pseudomonic acid A.
• Structural Alterations in the Translational Attenuator of Constitutively Expressed ermC Genes