6pdw

Msp1-substrate complex in closed conformationMsp1-substrate complex in closed conformation

6pdw, resolution 3.10Å Show:Asymmetric Unit Biological Assembly Structural highlights 6pdw is a 6 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed The AAA protein Msp1 extracts mislocalized tail-anchored membrane proteins and targets them for degradation, thus maintaining proper cell organization. How Msp1 selects its substrates and firmly engages them during the energetically unfavorable extraction process remains a mystery. To address this question, we solved cryo-EM structures of Msp1-substrate complexes at near-atomic resolution. Akin to other AAA proteins, Msp1 forms hexameric spirals that translocate substrates through a central pore. A singular hydrophobic substrate recruitment site is exposed at the spiral's seam, which we propose positions the substrate for entry into the pore. There, a tight web of aromatic amino acids grips the substrate in a sequence-promiscuous, hydrophobic milieu. Elements at the intersubunit interfaces coordinate ATP hydrolysis with the subunits' positions in the spiral. We present a comprehensive model of Msp1's mechanism, which follows general architectural principles established for other AAA proteins yet specializes Msp1 for its unique role in membrane protein extraction. Structure of the AAA protein Msp1 reveals mechanism of mislocalized membrane protein extraction.,Wang L, Myasnikov A, Pan X, Walter P Elife. 2020 Jan 30;9. pii: 54031. doi: 10.7554/eLife.54031. PMID:31999255 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.