RT Journal Article
SR Electronic
T1 The role of the first transmembrane helix in bacterial YidC: Insights from the crystal structure and molecular dynamics simulations
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.07.15.452481
DO 10.1101/2021.07.15.452481
A1 Karol J. Nass
A1 Ioana M. Ilie
A1 Manfred J. Saller
A1 Arnold J.M. Driessen
A1 Amedeo Caflisch
A1 Richard A. Kammerer
A1 Xiaodan Li
YR 2021
UL http://biorxiv.org/content/early/2021/07/19/2021.07.15.452481.abstract
AB The evolutionary conserved YidC is a unique dual-function protein that adopts insertase and chaperone conformations. The TM1 helix of Escherichia coli YidC mediates the interaction between the YidC chaperone and the Sec translocon. Here, we report the first crystal structure of Thermotoga maritima YidC (TmYidC) including the TM1 helix (PDB ID: 6Y86). The TM1 helix lies on the periplasmic side of the bilayer forming an angle of about 15 degrees with the membrane surface. Our functional studies suggest a role of TM1 for the species-specific interaction with the Sec translocon. The reconstitution data and the superimposition of TmYidC with known YidC structures suggest an active insertase conformation for YidC. Molecular dynamics (MD) simulations of TmYidC provide evidence that the TM1 helix acts as a membrane anchor for the YidC insertase and highlight the flexibility of the C1 region underlining its ability to switch between insertase and chaperone conformations. A structure-based model is proposed to rationalize how YidC performs the insertase and chaperone functions by re-positioning of the TM1 helix and the other structural elements.Competing Interest StatementThe authors have declared no competing interest.