Molecular architecture of the ER translocase probed by chemical crosslinking of Sss1p to complementary fragments of Sec61p.
The heterotrimeric Sec61p complex is a key component of the protein translocation apparatus of the endoplasmic reticulum membrane. The complex characterized from yeast includes Sec61p, a 10-transmembrane-domain membrane protein which has a direct interaction with Sss1p, a small C-terminal anchor protein. In order to gain some insight into the architecture of this complex we have functionally expressed Sec61p as complementary N- and C-terminal fragments. Chemical crosslinking of Sss1p to specific Sec61p fragments in these functional combinations and suppression of sec61 mutants by over-expression of Sss1p have led to identification of the region which includes transmembrane domains TM6, TM7 and TM8 (amino acid residues L232-R406) of Sec61p as a major site of interaction with Sss1p.
Wilkinson
B M
BM
School of Biological Sciences, University of Manchester, UK.
Esnault
Y
Y
Craven
R A
RA
Skiba
F
F
Fieschi
J
J
K'epès
F
F
Stirling
C J
CJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D001693:Biological Transport, Active; D003432:Cross-Linking Reagents; D017931:DNA Primers / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D000069816:SEC Translocation Channels; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins
D003432:Cross-Linking Reagents; D017931:DNA Primers; D005656:Fungal Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010446:Peptide Fragments; D000069816:SEC Translocation Channels; C499383:SEC61 protein, S cerevisiae; C084005:SSS1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins