Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

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

Macromolecule Content

• Total Structure Weight: 31.08 kDa 
• Atom Count: 2243 
• Residue Count: 271 
• Unique protein chains: 1

3QDH

Crystal structure of Actinomyces fimbrial adhesin FimA

• DOI: 10.2210/pdb3QDH/pdb

• Classification: CELL ADHESION
• Organism(s): Actinomyces naeslundii
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2011-01-18 Released: 2011-08-24 
• Deposition Author(s): Devarajan, B., Krishnan, V., Narayana, S.V.L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.249 
• R-Value Work: 0.209 
• R-Value Observed: 0.211 

Literature

Two autonomous structural modules in the fimbrial shaft adhesin FimA mediate Actinomyces interactions with streptococci and host cells during oral biofilm development.

Mishra, A., Devarajan, B., Reardon, M.E., Dwivedi, P., Krishnan, V., Cisar, J.O., Das, A., Narayana, S.V., Ton-That, H.

(2011) Mol Microbiol 81: 1205-1220

• PubMed: 21696465 
• DOI: 10.1111/j.1365-2958.2011.07745.x
• Structures With Same Primary Citation


• PubMed Abstract: 
  

By combining X-ray crystallography and modelling, we describe here the atomic structure of distinct adhesive moieties of FimA, the shaft fimbrillin of Actinomyces type 2 fimbriae, which uniquely mediates the receptor-dependent intercellular interactions between Actinomyces and oral streptococci as well as host cells during the development of oral biofilms. The FimA adhesin is built with three IgG-like domains, each of which harbours an intramolecular isopeptide bond, previously described in several Gram-positive pilins. Genetic and biochemical studies demonstrate that although these isopeptide bonds are dispensable for fimbrial assembly, cell-cell interactions and biofilm formation, they contribute significantly to the proteolytic stability of FimA. Remarkably, FimA harbours two autonomous adhesive modules, which structurally resemble the Staphylococcus aureus Cna B domain. Each isolated module can bind the plasma glycoprotein asialofetuin as well as the polysaccharide receptors present on the surface of oral streptococci and epithelial cells. Thus, FimA should serve as an excellent paradigm for the development of therapeutic strategies and elucidating the precise molecular mechanisms underlying the interactions between cellular receptors and Gram-positive fimbriae.

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Organizational Affiliation: 

Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Fimbrial structural subunit	A	290	Actinomyces naeslundii	Mutation(s): 0  Gene Names: fimA
Find proteins for O68212 (Actinomyces naeslundii) Go to UniProtKB:  O68212

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	A	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.249 
• R-Value Work: 0.209 
• R-Value Observed: 0.211 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 47.528	α = 90
b = 39.799	β = 98.34
c = 77.139	γ = 90

Software Package:

Software Name	Purpose
autoSHARP	phasing
REFMAC	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-01-18 
• Released Date: 2011-08-24 
Deposition Author(s): Devarajan, B., Krishnan, V., Narayana, S.V.L.

Revision History 

• Version 1.0: 2011-08-24
  Type: Initial release
  
• Version 1.1: 2011-09-14
  Changes: Database references