Portal from the Borrelia bacteriophage BB1 procapsid

Experimental Data Snapshot

  • Resolution: 2.34 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Model: in silico
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Structure of the Borrelia Bacteriophage phi BB1 Procapsid.

Rumnieks, J.Fuzik, T.Tars, K.

(2023) J Mol Biol 435: 168323-168323

  • DOI: https://doi.org/10.1016/j.jmb.2023.168323
  • Primary Citation of Related Structures:  
    8PHO, 8PHP, 8PHQ, 8PHR, 8PHS, 8PHT, 8PHU, 8PKH, 8QO0, 8QO1

  • PubMed Abstract: 

    Bacteriophages of Borrelia burgdorferi are a biologically important but under-investigated feature of the Lyme disease-causing spirochete. No virulent borrelial viruses have been identified, but all B. burgdorferi isolates carry a prophage φBB1 as resident circular plasmids. Like its host, the φBB1 phage is quite distinctive and shares little sequence similarity with other known bacteriophages. We expressed φBB1 head morphogenesis proteins in Escherichia coli which resulted in assembly of homogeneous prolate procapsid structures and used cryo-electron microscopy to determine the three-dimensional structure of these particles. The φBB1 procapsids consist of 415 copies of the major capsid protein and an equal combined number of three homologous capsid decoration proteins that form trimeric knobs on the outside of the particle. One of the end vertices of the particle is occupied by a portal assembled from twelve copies of the portal protein. The φBB1 scaffolding protein is entirely α-helical and has an elongated shape with a small globular domain in the middle. Within the tubular section of the procapsid, the internal scaffold is built of stacked rings, each composed of 32 scaffolding protein molecules, which run in opposite directions from both caps with a heterogeneous part in the middle. Inside the portal-containing cap, the scaffold is organized asymmetrically with ten scaffolding protein molecules bound to the portal. The φBB1 procapsid structure provides better insight into the vast structural diversity of bacteriophages and presents clues of how elongated bacteriophage particles might be assembled.

  • Organizational Affiliation

    Latvian Biomedical Research and Study Center, Rātsupītes 1, 1067 Riga, Latvia. Electronic address: j.rumnieks@biomed.lu.lv.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Phage portal protein407Borreliella burgdorferi B31Mutation(s): 0 
Gene Names: BB_L01
Find proteins for Q9R3K2 (Borreliella burgdorferi (strain ATCC 35210 / DSM 4680 / CIP 102532 / B31))
Explore Q9R3K2 
Go to UniProtKB:  Q9R3K2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9R3K2
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.34 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
European Regional Development FundEuropean Union1.1.1.2/VIAA/4/20/704
iNEXT-DiscoveryEuropean Union18826
iNEXT-DiscoveryEuropean Union24421

Revision History  (Full details and data files)

  • Version 1.0: 2023-07-12
    Type: Initial release
  • Version 1.1: 2023-11-01
    Changes: Data collection, Database references
  • Version 1.2: 2023-11-15
    Changes: Database references