The translocation site (translocon), at which nascent polypeptides pass through the endoplasmic reticulum membrane, contains a component previously called ‘signal sequence receptor’ that is now renamed as ‘translocon‐associated protein’ (TRAP). Two glycosylated subunits of the TRAP complex have been identified before (α and β subunits). We now show that the TRAP complex is actually comprised of four membrane proteins (α, β, γ, δ), present in a stoichiometric relation, which are genuine neighbours in intact microsomes. The amino acid sequences of the additional, non‐glycosylated subunits were deduced from cloning of the corresponding cDNAs. The δ subunit spans the membrane only once and has its major portion, containing a disulfide bridge, at the lumenal side. The γ subunit is predicted to span the membrane four times.
|Zeitschrift||European Journal of Biochemistry|
|Seiten (von - bis)||375-381|
|Publikationsstatus||Veröffentlicht - 01.01.1993|