4KZ1

Crystal structure of the soluble domain of VirB8 from Bartonella grahamii


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.205 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural Insight into How Bacteria Prevent Interference between Multiple Divergent Type IV Secretion Systems.

Gillespie, J.J.Phan, I.Q.Scheib, H.Subramanian, S.Edwards, T.E.Lehman, S.S.Piitulainen, H.Rahman, M.S.Rennoll-Bankert, K.E.Staker, B.L.Taira, S.Stacy, R.Myler, P.J.Azad, A.F.Pulliainen, A.T.

(2015) mBio 6: e01867-e01815

  • DOI: 10.1128/mBio.01867-15
  • Primary Citation of Related Structures:  
    4NHF, 4O3V, 4KZ1, 4LSO, 4MEI, 4JF8

  • PubMed Abstract: 
  • Prokaryotes use type IV secretion systems (T4SSs) to translocate substrates (e.g., nucleoprotein, DNA, and protein) and/or elaborate surface structures (i.e., pili or adhesins). Bacterial genomes may encode multiple T4SSs, e.g., there are three functionally divergent T4SSs in some Bartonella species (vir, vbh, and trw) ...

    Prokaryotes use type IV secretion systems (T4SSs) to translocate substrates (e.g., nucleoprotein, DNA, and protein) and/or elaborate surface structures (i.e., pili or adhesins). Bacterial genomes may encode multiple T4SSs, e.g., there are three functionally divergent T4SSs in some Bartonella species (vir, vbh, and trw). In a unique case, most rickettsial species encode a T4SS (rvh) enriched with gene duplication. Within single genomes, the evolutionary and functional implications of cross-system interchangeability of analogous T4SS protein components remains poorly understood. To lend insight into cross-system interchangeability, we analyzed the VirB8 family of T4SS channel proteins. Crystal structures of three VirB8 and two TrwG Bartonella proteins revealed highly conserved C-terminal periplasmic domain folds and dimerization interfaces, despite tremendous sequence divergence. This implies remarkable structural constraints for VirB8 components in the assembly of a functional T4SS. VirB8/TrwG heterodimers, determined via bacterial two-hybrid assays and molecular modeling, indicate that differential expression of trw and vir systems is the likely barrier to VirB8-TrwG interchangeability. We also determined the crystal structure of Rickettsia typhi RvhB8-II and modeled its coexpressed divergent paralog RvhB8-I. Remarkably, while RvhB8-I dimerizes and is structurally similar to other VirB8 proteins, the RvhB8-II dimer interface deviates substantially from other VirB8 structures, potentially preventing RvhB8-I/RvhB8-II heterodimerization. For the rvh T4SS, the evolution of divergent VirB8 paralogs implies a functional diversification that is unknown in other T4SSs. Collectively, our data identify two different constraints (spatiotemporal for Bartonella trw and vir T4SSs and structural for rvh T4SSs) that mediate the functionality of multiple divergent T4SSs within a single bacterium.


    Organizational Affiliation

    Department of Biosciences, University of Helsinki, Helsinki, Finland Institute of Biomedicine, University of Turku, Turku, Finland JGillespie@som.umaryland.edu arto.pulliainen@utu.fi.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
VirB8 proteinA181Bartonella grahamii as4aupMutation(s): 0 
Gene Names: Bgr_14870virB8
UniProt
Find proteins for C6AER9 (Bartonella grahamii (strain as4aup))
Explore C6AER9 
Go to UniProtKB:  C6AER9
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.62α = 90
b = 60.62β = 90
c = 124.57γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
XDSdata reduction

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-03-12
    Type: Initial release
  • Version 1.1: 2015-12-16
    Changes: Database references
  • Version 1.2: 2016-03-23
    Changes: Database references