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.
Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA.
Nil
N
Celebi
Liang
L
Yi
Sandra J
SJ
Facey
Andreas
A
Kuhn
Ross E
RE
Dalbey
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