How hibernation factors RMF, HPF, and YfiA turn off protein synthesis.
Eubacteria inactivate their ribosomes as 100S dimers or 70S monomers upon entry into stationary phase. In Escherichia coli, 100S dimer formation is mediated by ribosome modulation factor (RMF) and hibernation promoting factor (HPF), or alternatively, the YfiA protein inactivates ribosomes as 70S monomers. Here, we present high-resolution crystal structures of the Thermus thermophilus 70S ribosome in complex with each of these stationary-phase factors. The binding site of RMF overlaps with that of the messenger RNA (mRNA) Shine-Dalgarno sequence, which prevents the interaction between the mRNA and the 16S ribosomal RNA. The nearly identical binding sites of HPF and YfiA overlap with those of the mRNA, transfer RNA, and initiation factors, which prevents translation initiation. The binding of RMF and HPF, but not YfiA, to the ribosome induces a conformational change of the 30S head domain that promotes 100S dimer formation.
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA.
SourceScience (New York, N.Y.) 336:6083 2012 May 18 pg 915-8
Escherichia coli Proteins
Peptide Chain Initiation, Translational
Prokaryotic Initiation Factors
Protein Structure, Tertiary
RNA, Ribosomal, 16S
Ribosome Subunits, Small, Bacterial
Pub Type(s)Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't