Structural identity between the NH2-terminal domain of the rat and human ornithine carbamyltransferase "targeting" sequences.
Analysis of the secondary structure of human and rat ornithine carbamyltransferase's targeting sequence revealed the presence of a highly homologous domain with the following key features: an hydrophobic patch opposite to an hydrophilic surface characterized by the disposition of basic residues at potentially strategic positions. The functional role of this domain was established using a synthetic peptide corresponding to amino acids 1-19 of the rat ornithine carbamyltransferase precursor (pOCT 1-19). When added to an in vitro import assay system, pOCT (1-19) blocked the import of pOCT specifically: it did not impede the entry and processing of the precursor to subunit 2 of the F1-ATPase (p beta). This finding suggests that at least two distinct precursor(s)-specific pathways are required for the import of mitochondrial inner membrane and matrix proteins.
Côté
C
C
Université du Québec à Montréal, Department of Chemistry, Canada.
Poirier
J
J
Boulet
D
D
Dionne
G
G
Lacroix
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D006801:Humans; D007163:Immunosorbent Techniques; D008564:Membrane Potentials; D008928:Mitochondria / Q000201:enzymology; D008929:Mitochondria, Heart / Q000201:enzymology; D008969:Molecular Sequence Data; D009861:Onium Compounds / Q000378:metabolism; D009954:Ornithine Carbamoyltransferase / Q000378:metabolism; D011487:Protein Conformation; D011498:Protein Precursors / Q000378:metabolism; D021382:Protein Sorting Signals; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D013154:Spleen / Q000201:enzymology; D014320:Triphenylmethyl Compounds / Q000378:metabolism
D009861:Onium Compounds; D011498:Protein Precursors; D021382:Protein Sorting Signals; D014320:Triphenylmethyl Compounds; C011561:triphenylmethylphosphonium; D009954:Ornithine Carbamoyltransferase