TRAM translocating chain-associated

Other proteins also participate in the integration process. One class is composed of molecular chaperones such as SecA in bacteria and Hsp70 or BiP in eukaryotes (Qi and Bernstein, 1999 Schekman, 1994 Mothes et al., 1997 Hamman et al., 1998 Pilon and Schekman, 1999). Another important player in the eukaryotic system is TRAM (translocating chain-associating membrane protein) (Walter, 1992). 

Figure 13.20 Diagrams for eukaryotic translocations across the ER membrane. The mammalian co-tanslational translocation (a) and yeast post-translational translocation (b) of polypeptide chain are diagrammatically represented. Abbreviations used are SRP, signal recognition particle SR, SRP receptor and TRAM, translocating chain-associated membrane protein. Sec61p spans the ER membrane multiple times and likely forms the translocation channel. The cytosolic components, SsalP and Ydjlp which maintain the nascent polypeptide chain in the unfolded state in the post-translational translocation. The nascent polypeptide-associated complex (NAC) which maintains the fidelity of co-translational precursor and the role of GTP are not shown...

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