3FRR

Structure of human IST1(NTD) - (residues 1-189)(P21)

Summary for 3FRR

• Entry DOI: 10.2210/pdb3frr/pdb
• Related: 3FRS 3FRT 3FRV
• Descriptor: Uncharacterized protein KIAA0174 (2 entities in total)
• Functional Keywords: escrt, escrt-iii, chmp, ist1, alternative splicing, phosphoprotein, protein binding
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasmic vesicle : P53990
• Total number of polymer chains: 1
• Total formula weight: 21769.48

Authors

Schubert, H.L.,Hill, C.P.,Bajorek, M.,Sundquist, W.I. (deposition date: 2009-01-08, release date: 2009-06-30, Last modification date: 2023-09-06)

Primary citation

Bajorek, M.,Schubert, H.L.,McCullough, J.,Langelier, C.,Eckert, D.M.,Stubblefield, W.M.,Uter, N.T.,Myszka, D.G.,Hill, C.P.,Sundquist, W.I.
Structural basis for ESCRT-III protein autoinhibition.
Nat.Struct.Mol.Biol., 16:754-762, 2009

PubMed Abstract: Endosomal sorting complexes required for transport-III (ESCRT-III) subunits cycle between two states: soluble monomers and higher-order assemblies that bind and remodel membranes during endosomal vesicle formation, midbody abscission and enveloped virus budding. Here we show that the N-terminal core domains of increased sodium tolerance-1 (IST1) and charged multivesicular body protein-3 (CHMP3) form equivalent four-helix bundles, revealing that IST1 is a previously unrecognized ESCRT-III family member. IST1 and its ESCRT-III binding partner, CHMP1B, both form higher-order helical structures in vitro, and IST1-CHMP1 interactions are required for abscission. The IST1 and CHMP3 structures also reveal that equivalent downstream alpha5 helices can fold back against the core domains. Mutations within the CHMP3 core-alpha5 interface stimulate the protein's in vitro assembly and HIV-inhibition activities, indicating that dissociation of the autoinhibitory alpha5 helix from the core activates ESCRT-III proteins for assembly at membranes.

PubMed: 19525971
DOI: 10.1038/nsmb.1621

Experimental method

X-RAY DIFFRACTION (1.8 Å)