7RUA

Metazoan pre-targeting GET complex (cBUGG-out)

Summary for 7RUA

• Entry DOI: 10.2210/pdb7rua/pdb
• Related: 7RU9
• EMDB information: 24700 24701
• Descriptor: ATPase GET3, Golgi to ER traffic protein 4 homolog, Large proline-rich protein BAG6, ... (7 entities in total)
• Functional Keywords: atpase, complex, membrane protein chaperone, chaperone
• Biological source: Danio rerio (Zebrafish, Brachydanio rerio); More
• Total number of polymer chains: 8
• Total formula weight: 219106.11

Authors

Keszei, A.F.A.,Yip, M.C.J.,Shao, S. (deposition date: 2021-08-16, release date: 2021-12-15, Last modification date: 2024-06-05)

Primary citation

Keszei, A.F.A.,Yip, M.C.J.,Hsieh, T.C.,Shao, S.
Structural insights into metazoan pretargeting GET complexes.
Nat.Struct.Mol.Biol., 28:1029-1037, 2021

PubMed Abstract: Close coordination between chaperones is essential for protein biosynthesis, including the delivery of tail-anchored (TA) proteins containing a single C-terminal transmembrane domain to the endoplasmic reticulum (ER) by the conserved GET pathway. For successful targeting, nascent TA proteins must be promptly chaperoned and loaded onto the cytosolic ATPase Get3 through a transfer reaction involving the chaperone SGTA and bridging factors Get4, Ubl4a and Bag6. Here, we report cryo-electron microscopy structures of metazoan pretargeting GET complexes at 3.3-3.6 Å. The structures reveal that Get3 helix 8 and the Get4 C terminus form a composite lid over the Get3 substrate-binding chamber that is opened by SGTA. Another interaction with Get4 prevents formation of Get3 helix 4, which links the substrate chamber and ATPase domain. Both interactions facilitate TA protein transfer from SGTA to Get3. Our findings show how the pretargeting complex primes Get3 for coordinated client loading and ER targeting.

PubMed: 34887561
DOI: 10.1038/s41594-021-00690-7

Experimental method

ELECTRON MICROSCOPY (3.4 Å)