A conformational switch in a regulated mRNA involves tertiary structure.
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.
Gluick
T C
TC
Johns Hopkins University, Department of Chemistry, Baltimore, MD 21218, USA.
Gerstner
R B
RB
Draper
D E
DE
D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011522:Protons; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D013816:Thermodynamics
D001426:Bacterial Proteins; D011522:Protons; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C031798:ribosomal protein S4; D008274:Magnesium