YidC and SecY mediate membrane insertion of a Type I transmembrane domain.
YidC has been identified recently as an evolutionary conserved factor that is involved in the integration of inner membrane proteins (IMPs) in Escherichia coli. The discovery of YidC has inspired the reevaluation of membrane protein assembly pathways in E. coli. In this study, we have analyzed the role of YidC in membrane integration of a widely used model IMP, leader peptidase (Lep). Site-directed photocross-linking experiments demonstrate that both YidC and SecY contact nascent Lep very early during biogenesis, at only 50-amino acid nascent chain length. At this length the first transmembrane domain (TM), which acquires a type I topology, is not even fully exposed outside the ribosome. The pattern of interactions appears dependent on the position of the cross-linking probe in the nascent chain. Upon elongation, nascent Lep remains close to YidC and comes into contact with lipids as well. Our results suggest a role for YidC in both the reception and lipid partitioning of type I TMs.
Houben
Edith N G
EN
Department of Microbiology, Institute of Molecular Biological Sciences, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands.
Urbanus
Malene L
ML
Van Der Laan
Martin
M
Ten Hagen-Jongman
Corinne M
CM
Driessen
Arnold J M
AJ
Brunner
Josef
J
Oudega
Bauke
B
Luirink
Joen
J
D001426:Bacterial Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism*; D008027:Light; D050356:Lipid Metabolism; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D008954:Models, Biological; D010741:Phospholipases A / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D012270:Ribosomes / Q000378:metabolism; D000069816:SEC Translocation Channels; D012697:Serine Endopeptidases / Q000378:metabolism; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; C057841:SecY protein, E coli; C412443:YIDC protein, E coli; D010741:Phospholipases A; D012697:Serine Endopeptidases; C026515:type I signal peptidase