Cloning and sequence analysis of the beta subunit of the human translocon-associated protein.

A cDNA corresponding to the beta subunit of the human translocon-associated protein was cloned and sequenced. The polypeptide is 183 amino acids long and 96% homologous to its canine counterpart. Both polypeptides contain a cleavable signal sequence, an NH2-terminal domain extruding in the endoplasmic reticulum lumen, a transmembrane domain and a COOH-terminal domain located in the cytoplasm.