Translation of RNAIII, theStaphylococcus aureusagr regulatory RNA molecule, can be activated by a 3′-end deletion

Abstract

RNAIII, an RNA molecule shown to encode δ-hemolysin and independently to regulate toxin synthesis in Staphylococcus aureus, is transcribed at the mid-exponential phase of growth, while its target genes are activated 2 h later, at the post-exponential phase of growth. We show here that the translation of RNAIII to the 26-amino acid peptide δ-hemolysin is delayed by 1 h, and that this delay is abolished when the 3′-end of this molecule is deleted. We suggest that structural changes of RNAIII to a translatable form of the molecule precede its regulation of target gene expression.