5BWK

6.0 A Crystal structure of a Get3-Get4-Get5 intermediate complex from S.cerevisiae

Summary for 5BWK

• Entry DOI: 10.2210/pdb5bwk/pdb
• Related: 5BW8
• Descriptor: ATPase GET3, Golgi to ER traffic protein 4, Ubiquitin-like protein MDY2, ... (4 entities in total)
• Functional Keywords: tail-anchored targeting, atpase, electrostatic interaction, hydrolase-transport complex, hydrolase/transport
• Biological source: Saccharomyces cerevisiae (strain RM11-1a) (Baker's yeast); More
• Cellular location: Cytoplasm : B3LGZ3 Q12125; Cytoplasm, cytosol: Q12285
• Total number of polymer chains: 24
• Total formula weight: 681286.95

Authors

Gristick, H.B.,Chartron, J.W.,Clemons, W.M. (deposition date: 2015-06-08, release date: 2015-10-14, Last modification date: 2024-10-23)

Primary citation

Gristick, H.B.,Rome, M.E.,Chartron, J.W.,Rao, M.,Hess, S.,Shan, S.O.,Clemons, W.M.
Mechanism of Assembly of a Substrate Transfer Complex during Tail-anchored Protein Targeting.
J.Biol.Chem., 290:30006-30017, 2015

PubMed Abstract: Tail-anchored (TA) proteins, defined as having a single transmembrane helix at their C terminus, are post-translationally targeted to the endoplasmic reticulum membrane by the guided entry of TA proteins (GET) pathway. In yeast, the handover of TA substrates is mediated by the heterotetrameric Get4/Get5 complex (Get4/5), which tethers the co-chaperone Sgt2 to the targeting factor, the Get3 ATPase. Binding of Get4/5 to Get3 is critical for efficient TA targeting; however, questions remain about the formation of the Get3·Get4/5 complex. Here we report crystal structures of a Get3·Get4/5 complex from Saccharomyces cerevisiae at 2.8 and 6.0 Å that reveal a novel interface between Get3 and Get4 dominated by electrostatic interactions. Kinetic and mutational analyses strongly suggest that these structures represent an on-pathway intermediate that rapidly assembles and then rearranges to the final Get3·Get4/5 complex. Furthermore, we provide evidence that the Get3·Get4/5 complex is dominated by a single Get4/5 heterotetramer bound to one monomer of a Get3 dimer, uncovering an intriguing asymmetry in the Get4/5 heterotetramer upon Get3 binding. Ultrafast diffusion-limited electrostatically driven Get3·Get4/5 association enables Get4/5 to rapidly sample and capture Get3 at different stages of the GET pathway.

PubMed: 26451041
DOI: 10.1074/jbc.M115.677328

Experimental method

X-RAY DIFFRACTION (6 Å)