Membrane biogenesis of subunit II of cytochrome bo oxidase: contrasting requirements for insertion of N-terminal and C-terminal domains.
The membrane assembly of the respiratory complexes requires the membrane insertases Oxa1 in mitochondria and YidC in bacteria. Oxa1 is responsible for the insertion of the mitochondrial cytochrome c oxidase subunit II (CoxII). Here, we investigated whether YidC, the bacterial Oxa1 homolog, plays a crucial role in the assembly of the bacterial subunit II (CyoA) of cytochrome bo oxidase. CyoA spans the membrane twice and is made with a cleavable signal peptide. We find that translocation of the short N-terminal domain of CyoA is YidC-dependent. In contrast, both the SecA/SecYEG complex and YidC are required for translocation of the large C-terminal domain. By studying the N-terminal domain of CyoA alone, we find that translocation is unaffected when SecE is depleted, suggesting that the YidC insertase on its own catalyzes membrane insertion of the N-terminal region of CyoA. Strikingly, we find that the translocation of the N-terminal domain is a prerequisite for translocation of the C-terminal domain in the full-length CyoA protein because translocation of the large C-terminal domain alone in a truncated CyoA derivative was observed in the absence of YidC. This work shows that the distinct domains of CyoA have different translocation requirements (YidC only and Sec/YidC) and confirms that the membrane biogenesis of subunit II of cytochrome oxidase in bacteria and mitochondria have conserved features.
Celebi
Nil
N
Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA.
Yi
Liang
L
Facey
Sandra J
SJ
Kuhn
Andreas
A
Dalbey
Ross E
RE
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D011487:Protein Conformation; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D021382:Protein Sorting Signals; D021122:Protein Subunits / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D011498:Protein Precursors; D021382:Protein Sorting Signals; D021122:Protein Subunits; D000069816:SEC Translocation Channels; C412443:YIDC protein, E coli; C038862:cytochrome o oxidase; D003576:Electron Transport Complex IV; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins