1V0A

Family 11 Carbohydrate-Binding Module of cellulosomal cellulase Lic26A-Cel5E of Clostridium thermocellum


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The Family 11 Carbohydrate-Binding Module of Clostridium Thermocellum Lic26A-Cel5E Accomodates Beta-1,4- and Beta-1,3-1,4-Mixed Linked Glucans at a Single Binding Site

Carvalho, A.L.Goyal, A.Prates, J.A.M.Bolam, D.N.Gilbert, H.J.Pires, V.M.R.Ferreira, L.M.A.Planas, A.Romao, M.J.Fontes, C.M.G.A.

(2004) J.Biol.Chem. 279: 34785

  • DOI: 10.1074/jbc.M405867200

  • PubMed Abstract: 
  • Modular glycoside hydrolases that attack recalcitrant polymers generally contain noncatalytic carbohydrate-binding modules (CBMs), which play a critical role in the action of these enzymes by localizing the appended catalytic domains onto the surface ...

    Modular glycoside hydrolases that attack recalcitrant polymers generally contain noncatalytic carbohydrate-binding modules (CBMs), which play a critical role in the action of these enzymes by localizing the appended catalytic domains onto the surface of insoluble polysaccharide substrates. Type B CBMs, which recognize single polysaccharide chains, display ligand specificities that are consistent with the substrates hydrolyzed by the associated catalytic domains. In enzymes that contain multiple catalytic domains with distinct substrate specificities, it is unclear how these different activities influence the evolution of the ligand recognition profile of the appended CBM. To address this issue, we have characterized the properties of a family 11 CBM (CtCBM11) in Clostridium thermocellum Lic26A-Cel5E, an enzyme that contains GH5 and GH26 catalytic domains that display beta-1,4- and beta-1,3-1,4-mixed linked endoglucanase activity, respectively. Here we show that CtCBM11 binds to both beta-1,4- and beta-1,3-1,4-mixed linked glucans, displaying K(a) values of 1.9 x 10(5), 4.4 x 10(4), and 2 x 10(3) m(-1) for Glc-beta1,4-Glc-beta1,4-Glc-beta1,3-Glc, Glc-beta1,4-Glc-beta1,4-Glc-beta1,4-Glc, and Glc-beta1,3-Glc-beta1,4-Glc-beta1,3-Glc, respectively, demonstrating that CBMs can display a preference for mixed linked glucans. To determine whether these ligands are accommodated in the same or diverse sites in CtCBM11, the crystal structure of the protein was solved to a resolution of 1.98 A. The protein displays a beta-sandwich with a concave side that forms a potential binding cleft. Site-directed mutagenesis revealed that Tyr(22), Tyr(53), and Tyr(129), located in the putative binding cleft, play a central role in the recognition of all the ligands recognized by the protein. We propose, therefore, that CtCBM11 contains a single ligand-binding site that displays affinity for both beta-1,4- and beta-1,3-1,4-mixed linked glucans.


    Organizational Affiliation

    Rede de Química e Technologia/Centro de Química Fina e Biotechnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ENDOGLUCANASE H
A
178Clostridium thermocellum (strain ATCC 27405 / DSM 1237 / NBRC 103400 / NCIMB 10682 / NRRL B-4536 / VPI 7372)Mutation(s): 0 
Gene Names: celH
EC: 3.2.1.4
Find proteins for P16218 (Clostridium thermocellum (strain ATCC 27405 / DSM 1237 / NBRC 103400 / NCIMB 10682 / NRRL B-4536 / VPI 7372))
Go to UniProtKB:  P16218
Small Molecules
Ligands 2 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
CA
Query on CA

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.193 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 75.143α = 90.00
b = 50.892β = 90.00
c = 40.868γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-01-12
    Type: Initial release
  • Version 1.1: 2011-05-07
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance