3RWN

Atomic structure of bacteriophage sf6 tail needle knob


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.00 Å
  • R-Value Free: 0.142 
  • R-Value Work: 0.133 
  • R-Value Observed: 0.133 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Atomic structure of bacteriophage Sf6 tail needle knob.

Bhardwaj, A.Molineux, I.J.Casjens, S.R.Cingolani, G.

(2011) J Biol Chem 286: 30867-30877

  • DOI: 10.1074/jbc.M111.260877
  • Primary Citation of Related Structures:  
    3RWN

  • PubMed Abstract: 
  • Podoviridae are double-stranded DNA bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. Within the tail apparatus of P22-like phages, a dedicated fiber known as the "tail needle" likely functions as a cell envelop ...

    Podoviridae are double-stranded DNA bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. Within the tail apparatus of P22-like phages, a dedicated fiber known as the "tail needle" likely functions as a cell envelope-penetrating device to promote ejection of viral DNA inside the host. In Sf6, a P22-like phage that infects Shigella flexneri, the tail needle presents a C-terminal globular knob. This knob, absent in phage P22 but shared in other members of the P22-like genus, represents the outermost exposed tip of the virion that contacts the host cell surface. Here, we report a crystal structure of the Sf6 tail needle knob determined at 1.0 Å resolution. The structure reveals a trimeric globular domain of the TNF fold structurally superimposable with that of the tail-less phage PRD1 spike protein P5 and the adenovirus knob, domains that in both viruses function in receptor binding. However, P22-like phages are not known to utilize a protein receptor and are thought to directly penetrate the host surface. At 1.0 Å resolution, we identified three equivalents of l-glutamic acid (l-Glu) bound to each subunit interface. Although intimately bound to the protein, l-Glu does not increase the structural stability of the trimer nor it affects its ability to self-trimerize in vitro. In analogy to P22 gp26, we suggest the tail needle of phage Sf6 is ejected through the bacterial cell envelope during infection and its C-terminal knob is threaded through peptidoglycan pores formed by glycan strands.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Gene 9 proteinABC161Shigella virus Sf6Mutation(s): 0 
Gene Names: 9
Find proteins for Q716G6 (Shigella phage Sf6)
Explore Q716G6 
Go to UniProtKB:  Q716G6
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GLU
Query on GLU

Download CCD File 
A, B, C
GLUTAMIC ACID
C5 H9 N O4
WHUUTDBJXJRKMK-VKHMYHEASA-N
 Ligand Interaction
PO4
Query on PO4

Download CCD File 
A
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.00 Å
  • R-Value Free: 0.142 
  • R-Value Work: 0.133 
  • R-Value Observed: 0.133 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.407α = 90
b = 88.325β = 90
c = 89.106γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
SOLVEphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-06-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2012-04-11
    Changes: Database references