6e11

PTEX Core Complex in the Resetting (Compact) StatePTEX Core Complex in the Resetting (Compact) State

6e11, resolution 4.23Å Show:Asymmetric Unit Biological Assembly Structural highlights 6e11 is a 27 chain structure with sequence from Plasmodium falciparum (isolate 3d7) and Plasmodium falciparum 3d7. 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 putative Plasmodium translocon of exported proteins (PTEX) is essential for transport of malarial effector proteins across a parasite-encasing vacuolar membrane into host erythrocytes, but the mechanism of this process remains unknown. Here we show that PTEX is a bona fide translocon by determining structures of the PTEX core complex at near-atomic resolution using cryo-electron microscopy. We isolated the endogenous PTEX core complex containing EXP2, PTEX150 and HSP101 from Plasmodium falciparum in the 'engaged' and 'resetting' states of endogenous cargo translocation using epitope tags inserted using the CRISPR-Cas9 system. In the structures, EXP2 and PTEX150 interdigitate to form a static, funnel-shaped pseudo-seven-fold-symmetric protein-conducting channel spanning the vacuolar membrane. The spiral-shaped AAA+ HSP101 hexamer is tethered above this funnel, and undergoes pronounced compaction that allows three of six tyrosine-bearing pore loops lining the HSP101 channel to dissociate from the cargo, resetting the translocon for the next threading cycle. Our work reveals the mechanism of P. falciparum effector export, and will inform structure-based design of drugs targeting this unique translocon. Malaria parasite translocon structure and mechanism of effector export.,Ho CM, Beck JR, Lai M, Cui Y, Goldberg DE, Egea PF, Zhou ZH Nature. 2018 Sep;561(7721):70-75. doi: 10.1038/s41586-018-0469-4. Epub 2018 Aug, 27. PMID:30150771 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Heat Shock Protein structures