The aromatic nature of residue 66 of the 11-kDa subunit of ubiquinol-cytochrome c oxidoreductase of the yeast Saccharomyces cerevisiae is important for the assembly of a functional enzyme.
Transformation of multi- and single-copy plasmids carrying a mutated version (LTN2, region 66-YWYWW-70 replaced by SASAA) of QCR8, the gene encoding the 11-kDa subunit ubiquinol-cytochrome c oxidoreductase of Saccharomyces cerevisiae, to a QCR8(0) strain indicated the importance of this aromatic region for the assembly of a functional enzyme. Sequencing of plasmids giving spontaneous restoration of growth to some colonies among the single-copy LTN2 transformants showed that changing the sequence SASAA into the sequence FASAA could, to a large extent, overcome the observed assembly defect, indicating the importance of the aromatic nature of residue 66.
Hemrika
W
W
E.C. Slater Institute, University of Amsterdam, The Netherlands.
Lobo-Hajdu
G
G
Berden
J A
JA
Grivell
L A
LA
D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D014450:Electron Transport Complex III / Q000737:chemistry* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D018014:Gene Transfer Techniques; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D017421:Sequence Analysis; D013329:Structure-Activity Relationship
D014450:Electron Transport Complex III