6PVR | pdb_00006pvr

Influenza B M2 Proton Channel in the Closed State - SSNMR Structure at pH 7.5

• PDB DOI: https://doi.org/10.2210/pdb6PVR/pdb
• BMRB: 30645

• Classification: VIRAL PROTEIN
• Organism(s): Influenza B virus (B/Maryland/1/2001)
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2019-07-21 Released: 2020-02-05 
• Deposition Author(s): Mandala, V.S., Loftis, A.R., Shcherbakov, A.S., Pentelute, B.L., Hong, M.
• Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

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Experimental Data Snapshot

• Method: SOLID-STATE NMR
• Conformers Calculated: 120 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 

Literature

Atomic structures of closed and open influenza B M2 proton channel reveal the conduction mechanism.

Mandala, V.S., Loftis, A.R., Shcherbakov, A.A., Pentelute, B.L., Hong, M.

(2020) Nat Struct Mol Biol 27: 160-167

• PubMed: 32015551 
• DOI: https://doi.org/10.1038/s41594-019-0371-2
• Primary Citation Related Structures: 
  6PVR, 6PVT


• PubMed Abstract: 
  

  The influenza B M2 (BM2) proton channel is activated by acidic pH to mediate virus uncoating. Unlike influenza A M2 (AM2), which conducts protons with strong inward rectification, BM2 conducts protons both inward and outward. Here we report 1.4- and 1.5-Å solid-state NMR structures of the transmembrane domain of the closed and open BM2 channels in a phospholipid environment. Upon activation, the transmembrane helices increase the tilt angle by 6° and the average pore diameter enlarges by 2.1 Å. BM2 thus undergoes a scissor motion for activation, which differs from the alternating-access motion of AM2. These results indicate that asymmetric proton conduction requires a backbone hinge motion, whereas bidirectional conduction is achieved by a symmetric scissor motion. The proton-selective histidine and gating tryptophan in the open BM2 reorient on the microsecond timescale, similar to AM2, indicating that side chain dynamics are the essential driver of proton shuttling.

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Organizational Affiliation: 
• Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA. [e-mail].

Biological Assembly 1  

Global Symmetry: Cyclic - C4  (Explore in 3D)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: assay for oligomerization

Macromolecule Content 

• Total Structure Weight: 23.81 kDa 
• Atom Count: 1,092 
• Modeled Residue Count: 132 
• Deposited Residue Count: 204 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
BM2 protein	A, B, C, D	51	Influenza B virus (B/Maryland/1/2001)	Mutation(s): 0  Gene Names: BM2

Experimental Data & Validation

Experimental Data

• Method: SOLID-STATE NMR
• Conformers Calculated: 120 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2020-02-05 
Deposition Author(s): Mandala, V.S., Loftis, A.R., Shcherbakov, A.S., Pentelute, B.L., Hong, M.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	GM088204

Revision History  

• Version 1.0: 2020-02-05
  Type: Initial release
  
• Version 1.1: 2020-02-19
  Changes: Database references
• Version 1.2: 2020-02-26
  Changes: Database references
• Version 1.3: 2024-05-01
  Changes: Data collection, Database references