Direct interaction of YidC with the Sec-independent Pf3 coat protein during its membrane protein insertion.
YidC is a newly defined translocase component that mediates the insertion of proteins into the membrane bilayer. How YidC functions in the insertion process is not known. In this study, we report that the Sec-independent Pf3 coat protein requires the YidC protein specifically for the membrane translocation step. Using photocrosslinking techniques and ribosome-bound Pf3 coat derivatives with an extended carboxyl-terminal region, we found that the transmembrane region of the Pf3 coat protein physically interacts with YidC and the bacterial signal recognition particle Ffh component. We also find that in the insertion pathway, Pf3 coat interacts strongly with YidC only after its transmembrane segment is fully exposed outside the ribosome tunnel. Interaction between Pf3 coat and YidC occurs even in the absence of the proton motive force and with a Pf3 coat mutant that is defective in transmembrane insertion. Our study demonstrates that YidC can directly interact with a Sec-independent membrane protein, and the role of YidC is at the stage of folding the Pf3 protein into a transmembrane configuration.
Chen
Minyong
M
Department of Chemistry, Ohio State Biochemistry Program, and Protein Research Group, The Ohio State University, Columbus, Ohio 43210, USA.
Samuelson
James C
JC
Jiang
Fenglei
F
Muller
Matthias
M
Kuhn
Andreas
A
Dalbey
Ross E
RE
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D002213:Capsid / Q000737:chemistry / Q000378:metabolism*; D036022:Capsid Proteins; D002254:Carbonates / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D003062:Codon; D003432:Cross-Linking Reagents / Q000494:pharmacology; D019281:Dimerization; D010450:Endopeptidases / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D008954:Models, Biological; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011522:Protons; D012270:Ribosomes / Q000378:metabolism; D013997:Time Factors
D001426:Bacterial Proteins; D036022:Capsid Proteins; D002254:Carbonates; D003062:Codon; D003432:Cross-Linking Reagents; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D011522:Protons; C412443:YIDC protein, E coli; C005686:sodium carbonate; C084332:major coat protein, Pseudomonas phage Pf3; D010450:Endopeptidases