Year: 2023
Type: article
Abstract: The universally conserved protein YidC aids the insertion and folding of transmembrane polypeptides independently or as a part of the SecYEG translocon complex. In the former scenario, the lipid-exposed YidC surface equipped with a highly conserved positively charged arginine is thought to facilitate membrane insertion of the nascent chain by providing a countercharge for the acidic residues at the polypeptide’s N-terminal region. Here we show that the purified and reconstituted E. coli YidC forms an ion-conducting transmembrane pore upon binding a ribosome or ribosome-nascent chain complex (RNC). This pore is closed in the absence of ribosomes. As this pore is not visible in the published monomeric YidC structure, we used AlphaFold to construct the model of a parallel YidC dimer. Experimental evidence for a dimeric assembly comes from our BN-PAGE analysis of native vesicles, fluorescence correlation spectroscopy studies, and single-molecule fluorescence microscopy. In the dimeric model, the conserved positively charged arginine and many residues interacting with nascent chains point into the putative pore. This result suggests the possibility of an alternative mode of YidC-assisted membrane protein insertion.
Source: Biomolecules
DOI: 10.3390/biom13121774
Authors: Denis G. Knyazev, Lukas Winter, Andreas Vogt, Sandra Posch, Yavuz Öztürk, Christine Siligan, Nikolaus Goessweiner-Mohr, Nora Hagleitner-Ertugrul, Hans-Georg Koch, Peter Pohl
Institutions: Johannes Kepler University of Linz, University of Freiburg
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,558
Awards: G1514386576, G2047871659, G2515931259, G293965311, G297512995, G3047102799, G3699921127, G4773263302, G488616897, G501584059, G5225139163, G52271539, G5346208307, G5563840597, Proton gradients in bacterial protein translocation, Translocon based development of antiviral compounds, G6475523640, G8642428559, SFB 1381: Dynamische Organisation zellulärer Proteinmaschinerien: Von der Biogenese und modularen Assemblierung zur Funktion, G8894578234
OpenAlex ID: W4389558430