This family consists of several eukaryotic translocon-associated protein, gamma subunit (TRAP-gamma) sequences. 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). The TRAP complex is comprised of four membrane proteins alpha, beta, gamma and delta which are present in a stoichiometric relation, and are genuine neighbours in intact microsomes. The gamma subunit is predicted to span the membrane four times [1].

1: A tetrameric complex of membrane proteins in the endoplasmic reticulum. Hartmann E, Gorlich D, Kostka S, Otto A, Kraft R, Knespel S, Burger E, Rapoport TA, Prehn S; Eur J Biochem 1993;214:375-381. PMID:7916687