6tza

CryoEM reconstruction of ESCRT-III filament composed of IST1 NTD R16E K27E double mutantCryoEM reconstruction of ESCRT-III filament composed of IST1 NTD R16E K27E double mutant

Structural highlights 6tza is a 14 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: IST1, KIAA0174 (HUMAN) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [IST1_HUMAN] Proposed to be involved in specific functions of the ESCRT machinery. Is required for efficient abscission during cytokinesis, but not for HIV-1 budding. The involvement in the MVB pathway is not established. Involved in recruiting VPS4A and/or VPS4B to the midbody of dividing cells. Publication Abstract from PubMed The endosomal sorting complexes required for transport (ESCRTs) mediate diverse membrane remodeling events. These typically require ESCRT-III proteins to stabilize negatively curved membranes; however, recent work has indicated that certain ESCRT-IIIs also participate in positive-curvature membrane-shaping reactions. ESCRT-IIIs polymerize into membrane-binding filaments, but the structural basis for negative versus positive membrane remodeling by these proteins remains poorly understood. To learn how certain ESCRT-IIIs shape positively curved membranes, we determined structures of human membrane-bound CHMP1B-only, membrane-bound CHMP1B + IST1, and IST1-only filaments by cryo-EM. Our structures show how CHMP1B first polymerizes into a single-stranded helical filament, shaping membranes into moderate-curvature tubules. Subsequently, IST1 assembles a second strand on CHMP1B, further constricting the membrane tube and reducing its diameter nearly to the fission point. Each step of constriction thins the underlying bilayer, lowering the barrier to membrane fission. Our structures reveal how a two-component, sequential polymerization mechanism drives membrane tubulation, constriction and bilayer thinning. Membrane constriction and thinning by sequential ESCRT-III polymerization.,Nguyen HC, Talledge N, McCullough J, Sharma A, Moss FR 3rd, Iwasa JH, Vershinin MD, Sundquist WI, Frost A Nat Struct Mol Biol. 2020 Apr;27(4):392-399. doi: 10.1038/s41594-020-0404-x. Epub, 2020 Apr 6. PMID:32251413 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 6tza, resolution 7.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image