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 
  • R-Value Observed: 0.195 

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
  • Primary Citation of Related Structures:  
    1V0A

  • 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 of insoluble polysaccharide substrates ...

    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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ENDOGLUCANASE HA178Acetivibrio thermocellusMutation(s): 0 
EC: 3.2.1.4
UniProt
Find proteins for P16218 (Hungateiclostridium thermocellum (strain ATCC 27405 / DSM 1237 / JCM 9322 / NBRC 103400 / NCIMB 10682 / NRRL B-4536 / VPI 7372))
Explore P16218 
Go to UniProtKB:  P16218
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
D [auth A], E [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CA
Query on CA

Download Ideal Coordinates CCD File 
B [auth A], C [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
AL-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 
  • R-Value Observed: 0.195 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 75.143α = 90
b = 50.892β = 90
c = 40.868γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

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