A conformational switch in a regulated mRNA involves tertiary structure
Gluick, T.C.; Gerstner, R.B.; Draper, D.E.
Nucleic Acids Symposium Series 33: 200-202
1995
ISSN/ISBN: 0261-3166 PMID: 8643369 Document Number: 454685
The E. coli alpha operon mRNA is autogenously regulated by binding the repressor ribosomal protein S4. Repression occurs via a novel mechanism in which S4 traps the mRNA in a conformation that prevents formation of the complete initiation complex. The conformations have similar stabilities but separated by a high activation energy which is a criterion for a conformational switch. The conformation switch is likely to involve alteration in tertiary structure as indicated by gel electrophoresis and thermal denaturation experiments. It was found that Mg2+ stabilizes the repressed form and tertiary structure, and H+ stabilizes the translated form and have complicated effects on tertiary structure.