Recognition of mitochondrial protein precursor lacking arginine at position -2 by mitochondrial processing peptidase: processing of bovine cytochrome P450(SCC) precursor.
Mitochondrial processing peptidase (MPP) specifically cleaves off the N-terminal presequence of the mitochondrial protein precursor. Previous studies demonstrated that Arg at position -2 from the cleavage site, which is found among many precursors, plays a critical role in recognition by MPP. We analyzed the structural elements of bovine cytochrome P450 side-chain cleavage enzyme precursor [pre-P450(SCC)], which has Ala at position -2, for recognition by MPP. Replacement of Ala position -2 of pre-P450(SCC) with Arg resulted in an increase in the cleavage rate. Replacement with Gly caused a reduction in the cleavage rate and the appearance of an additional cleavage site downstream of the authentic site. A pre-P450(SCC) mutant with Met at position -2 retained cleavage efficiency equal to that of the wild type. These results indicate that -2 Ala of pre-P450(SCC) is recognized by MPP as a determinant for precise cleavage, and that the amino acid at -2 is required to have a straight methylene chain for interaction with the S(2) site. The preference for distal basic residues, a hydrophobic residue at +1, and hydroxyl residues at +2 and +3, was almost the same as those of the precursors with Arg at -2, indicating that the recognition mechanism of pre-P450(SCC) by MPP is essentially the same as that of the precursors with Arg at position -2.
Kojima
K
K
Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan.
Yamasaki
E
E
Kitada
S
S
Ogishima
T
T
Ito
A
A
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001120:Arginine / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D020134:Catalytic Domain; D002417:Cattle; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004792:Enzyme Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008666:Metalloendopeptidases / Q000737:chemistry / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D011499:Protein Processing, Post-Translational; D016415:Sequence Alignment; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D000096122:Mitochondrial Processing Peptidase
D001120:Arginine; D002786:Cholesterol Side-Chain Cleavage Enzyme; D004792:Enzyme Precursors; D008666:Metalloendopeptidases; D000096122:Mitochondrial Processing Peptidase