4UMS

The crystal structure of the seventh ScaB type I cohesin from Pseudobacteroides cellulosolvens


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.84 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 

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This is version 1.2 of the entry. See complete history


Literature

Combined Crystal Structure of a Type-I Cohesin, Mutation and Affinity-Binding Studies Reveal Structural Determinants of Cohesin-Dockerin Specificity

Cameron, K.Alves, V.D.Bayer, E.A.Gilbert, H.J.Ferreira, L.M.A.Fontes, C.M.G.A.Najmudin, S.

(2015) J Biol Chem 290: 16215

  • DOI: 10.1074/jbc.M115.653303
  • Primary Citation of Related Structures:  
    4UMS

  • PubMed Abstract: 
  • Cohesin-dockerin interactions orchestrate the assembly of one of nature's most elaborate multienzyme complexes, the cellulosome. Cellulosomes are produced exclusively by anaerobic microbes and mediate highly efficient hydrolysis of plant structural p ...

    Cohesin-dockerin interactions orchestrate the assembly of one of nature's most elaborate multienzyme complexes, the cellulosome. Cellulosomes are produced exclusively by anaerobic microbes and mediate highly efficient hydrolysis of plant structural polysaccharides, such as cellulose and hemicellulose. In the canonical model of cellulosome assembly, type I dockerin modules of the enzymes bind to reiterated type I cohesin modules of a primary scaffoldin. Each type I dockerin contains two highly conserved cohesin-binding sites, which confer quaternary flexibility to the multienzyme complex. The scaffoldin also bears a type II dockerin that anchors the entire complex to the cell surface by binding type II cohesins of anchoring scaffoldins. In Bacteroides cellulosolvens, however, the organization of the cohesin-dockerin types is reversed, whereby type II cohesin-dockerin pairs integrate the enzymes into the primary scaffoldin, and type I modules mediate cellulosome attachment to an anchoring scaffoldin. Here, we report the crystal structure of a type I cohesin from B. cellulosolvens anchoring scaffoldin ScaB to 1.84-Å resolution. The structure resembles other type I cohesins, and the putative dockerin-binding site, centered at β-strands 3, 5, and 6, is likely to be conserved in other B. cellulosolvens type I cohesins. Combined computational modeling, mutagenesis, and affinity-based binding studies revealed similar hydrogen-bonding networks between putative Ser/Asp recognition residues in the dockerin at positions 11/12 and 45/46, suggesting that a dual-binding mode is not exclusive to the integration of enzymes into primary cellulosomes but can also characterize polycellulosome assembly and cell-surface attachment. This general approach may provide valuable structural information of the cohesin-dockerin interface, in lieu of a definitive crystal structure.


    Organizational Affiliation

    From the CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CELLULOSOMAL ANCHORING SCAFFOLDIN BA156Pseudobacteroides cellulosolvensMutation(s): 0 
Gene Names: scaB
Find proteins for Q6A564 (Pseudobacteroides cellulosolvens)
Explore Q6A564 
Go to UniProtKB:  Q6A564
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.84 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 30.382α = 90
b = 52.767β = 90
c = 90.457γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
Aimlessdata scaling
BALBESphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-05-06
    Type: Initial release
  • Version 1.1: 2015-05-13
    Changes: Database references
  • Version 1.2: 2015-07-08
    Changes: Database references