Sec61p contributes to signal sequence orientation according to the positive-inside rule.

ABSTRACT: Protein targeting to the endoplasmic reticulum is mediated by signal or signal-anchor sequences. They also play an important role in protein topogenesis, because their orientation in the translocon determines whether their N- or C-terminal sequence is translocated. Signal orientation is primarily determined by charged residues flanking the hydrophobic core, whereby the more positive end is predominantly positioned to the cytoplasmic side of the membrane, a phenomenon known as the "positive-inside rule." We tested the role of conserved charged residues of Sec61p, the major component of the translocon in Saccharomyces cerevisiae, in orienting signals according to their flanking charges by site-directed mutagenesis by using diagnostic model proteins. Mutation of R67, R74, or E382 in Sec61p re

SUBMITTER: Goder V 

PROVIDER: S-EPMC363169 | biostudies-literature | 2004 Mar

REPOSITORIES: biostudies-literature