Hemrika W, Lobo-Hajdu G, Berden J A, Grivell L A
E.C. Slater Institute, University of Amsterdam, The Netherlands.
FEBS Lett. 1994 May 9;344(1):15-9. doi: 10.1016/0014-5793(94)00346-7.
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.
