4IU2

Cohesin-dockerin -X domain complex from Ruminococcus flavefacience


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.001 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.153 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Atypical Cohesin-Dockerin Complex Responsible for Cell Surface Attachment of Cellulosomal Components: BINDING FIDELITY, PROMISCUITY, AND STRUCTURAL BUTTRESSES.

Salama-Alber, O.Jobby, M.K.Chitayat, S.Smith, S.P.White, B.A.Shimon, L.J.Lamed, R.Frolow, F.Bayer, E.A.

(2013) J.Biol.Chem. 288: 16827-16838

  • DOI: 10.1074/jbc.M113.466672
  • Primary Citation of Related Structures:  4IU3

  • PubMed Abstract: 
  • The rumen bacterium Ruminococcus flavefaciens produces a highly organized multienzyme cellulosome complex that plays a key role in the degradation of plant cell wall polysaccharides, notably cellulose. The R. flavefaciens cellulosomal system is ancho ...

    The rumen bacterium Ruminococcus flavefaciens produces a highly organized multienzyme cellulosome complex that plays a key role in the degradation of plant cell wall polysaccharides, notably cellulose. The R. flavefaciens cellulosomal system is anchored to the bacterial cell wall through a relatively small ScaE scaffoldin subunit, which bears a single type IIIe cohesin responsible for the attachment of two major dockerin-containing scaffoldin proteins, ScaB and the cellulose-binding protein CttA. Although ScaB recruits the catalytic machinery onto the complex, CttA mediates attachment of the bacterial substrate via its two putative carbohydrate-binding modules. In an effort to understand the structural basis for assembly and cell surface attachment of the cellulosome in R. flavefaciens, we determined the crystal structure of the high affinity complex (Kd = 20.83 nM) between the cohesin module of ScaE (CohE) and its cognate X-dockerin (XDoc) modular dyad from CttA at 1.97-Å resolution. The structure reveals an atypical calcium-binding loop containing a 13-residue insert. The results further pinpoint two charged specificity-related residues on the surface of the cohesin module that are responsible for specific versus promiscuous cross-strain binding of the dockerin module. In addition, a combined functional role for the three enigmatic dockerin inserts was established whereby these extraneous segments serve as structural buttresses that reinforce the stalklike conformation of the X-module, thus segregating its tethered complement of cellulosomal components from the cell surface. The novel structure of the RfCohE-XDoc complex sheds light on divergent dockerin structure and function and provides insight into the specificity features of the type IIIe cohesin-dockerin interaction.


    Organizational Affiliation

    Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cell-wall anchoring protein
A
212Ruminococcus flavefaciensGene Names: scaE
Find proteins for A0AEF6 (Ruminococcus flavefaciens)
Go to UniProtKB:  A0AEF6
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Cellulose-binding protein
B
243Ruminococcus flavefaciensGene Names: cttA
Find proteins for A0AEF5 (Ruminococcus flavefaciens)
Go to UniProtKB:  A0AEF5
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A, B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

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Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.001 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.153 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 78.714α = 90.00
b = 78.714β = 90.00
c = 203.238γ = 90.00
Software Package:
Software NamePurpose
SHELXSphasing
SCALEPACKdata scaling
HKL-2000data reduction
PHENIXrefinement
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-04-24
    Type: Initial release
  • Version 1.1: 2013-07-03
    Type: Database references