Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report

Global Symmetry: Cyclic - C6  (3D View)
Global Stoichiometry: Homo 18-mer - A18 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 467.01 kDa 
• Atom Count: 32490 
• Modelled Residue Count: 4230 
• Deposited Residue Count: 4230 
• Unique protein chains: 1

7ASL

HIV-1 Gag immature lattice. GagSP1T8I

• PDB DOI: 10.2210/pdb7ASL/pdb
• EM Map EMD-11897:EMDBEMDataResource

• Classification: VIRAL PROTEIN
• Organism(s): Human immunodeficiency virus 1
• Expression System: Homo sapiens
• Mutation(s): Yes 


• Deposited: 2020-10-27 Released: 2021-06-23 
• Deposition Author(s): Mendonca, L., Zhang, P.
• Funding Organization(s): Wellcome Trust

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 4.50 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SUBTOMOGRAM AVERAGING 

Literature

CryoET structures of immature HIV Gag reveal six-helix bundle.

Mendonca, L., Sun, D., Ning, J., Liu, J., Kotecha, A., Olek, M., Frosio, T., Fu, X., Himes, B.A., Kleinpeter, A.B., Freed, E.O., Zhou, J., Aiken, C., Zhang, P.

(2021) Commun Biol 4: 481-481

• PubMed: 33863979 
• DOI: 10.1038/s42003-021-01999-1
• Primary Citation of Related Structures:  
  7ASH, 7ASL


• PubMed Abstract: 
  

Gag is the HIV structural precursor protein which is cleaved by viral protease to produce mature infectious viruses. Gag is a polyprotein composed of MA (matrix), CA (capsid), SP1, NC (nucleocapsid), SP2 and p6 domains. SP1, together with the last eight residues of CA, have been hypothesized to form a six-helix bundle responsible for the higher-order multimerization of Gag necessary for HIV particle assembly. However, the structure of the complete six-helix bundle has been elusive. Here, we determined the structures of both Gag in vitro assemblies and Gag viral-like particles (VLPs) to 4.2 Å and 4.5 Å resolutions using cryo-electron tomography and subtomogram averaging by emClarity. A single amino acid mutation (T8I) in SP1 stabilizes the six-helix bundle, allowing to discern the entire CA-SP1 helix connecting to the NC domain. These structures provide a blueprint for future development of small molecule inhibitors that can lock SP1 in a stable helical conformation, interfere with virus maturation, and thus block HIV-1 infection.

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Organizational Affiliation: 

Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK. [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Gag protein	A, B, C, D, G [auth E], J [auth F], M [auth G], P [auth H], E [auth I], H [auth J], K, N [auth L], Q [auth M], F [auth N], I [auth O], L [auth P], O [auth Q], R	235	Human immunodeficiency virus 1	Mutation(s): 1  Gene Names: gag
UniProt
Find proteins for P04591 (Human immunodeficiency virus type 1 group M subtype B (isolate HXB2)) Explore P04591  Go to UniProtKB:  P04591

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 4.50 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SUBTOMOGRAM AVERAGING 

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2020-10-27 
• Released Date: 2021-06-23 
Deposition Author(s): Mendonca, L., Zhang, P.

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Funding Organization	Location	Grant Number
Wellcome Trust	United Kingdom	206422/Z/17/Z

Revision History  

• Version 1.0: 2021-06-23
  Type: Initial release
  
• Version 1.1: 2022-03-23
  Changes: Database references