RNA secondary structure and translation inhibition: analysis of mutants in the rplJ leader.

Abstract
Measurements were made of the stable binding of the ribosomal protein complex L10-L7/L12 to mutant forms of the mRNA leader of the rplJ operon of Escherichia coli. One of the point mutations, base 1548, which lies within the L10-L7/L12-protected region, almost completely abolishes in vitro formation of a stable complex of L10-L7/L12 with rplJ mRNA leader; a 2nd point mutation, base 1634, strongly reduces it. Thus, L10-L7/L12 evidently binds to the rplJ leader in bringing about translational feedback. To account for the action of these and other mutations, and to explain the mechanism of translation feedback inhibition, a secondary structure model involving alternate forms of the rplJ mRNA leader is suggested.