5OKE

Conservatively refined structure of Gan1D-E170Q, a catalytic mutant of a putative 6-phospho-beta-galactosidase from Geobacillus stearothermophilus, in complex with cellobiose-6-phosphate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.31 Å
  • R-Value Free: 0.155 
  • R-Value Work: 0.133 
  • R-Value Observed: 0.133 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 2.1 of the entry. See complete history


Literature

Structural basis for enzyme bifunctionality - the case of Gan1D from Geobacillus stearothermophilus.

Lansky, S.Zehavi, A.Belrhali, H.Shoham, Y.Shoham, G.

(2017) FEBS J 284: 3931-3953

  • DOI: https://doi.org/10.1111/febs.14283
  • Primary Citation of Related Structures:  
    5OK7, 5OKA, 5OKB, 5OKE, 5OKG, 5OKH, 5OKJ, 5OKK, 5OKQ, 5OKR, 5OKS

  • PubMed Abstract: 

    6-phospho-β-glucosidases and 6-phospho-β-galactosidases are enzymes that hydrolyze the β-glycosidic bond between a terminal non-reducing glucose-6-phosphate (Glc6P) or galactose-6-phosphate (Gal6P), respectively, and other organic molecules. Gan1D, a glycoside hydrolase (GH) belonging to the GH1 family, has recently been identified in a newly characterized galactan-utilization gene cluster in the bacterium Geobacillus stearothermophilus T-1. Gan1D has been shown to exhibit bifunctional activity, possessing both 6-phospho-β-galactosidase and 6-phospho-β-glucosidase activities. We report herein the complete 3D crystal structure of Gan1D, together with its acid/base catalytic mutant Gan1D-E170Q. The tertiary structure of Gan1D conforms well to the (β/α) 8 TIM-barrel fold commonly observed in GH enzymes, and its quaternary structure adopts a dimeric assembly, confirmed by gel-filtration and small-angle X-ray scattering results. We present also the structures of Gan1D in complex with the putative substrate cellobiose-6-phosphate (Cell6P) and the degradation products Glc6P and Gal6P. These complexes reveal the specific enzyme-substrate and enzyme-product binding interactions of Gan1D, and the residues involved in its glycone, aglycone, and phosphate binding sites. We show that the different ligands trapped in the active sites adopt different binding modes to the protein, providing a structural basis for the dual galactosidase/glucosidase activity observed for this enzyme. Based on this information, specific mutations were performed on one of the active site residues (W433), shifting the enzyme specificity from dual activity to a significant preference toward 6-phospho-β-glucosidase activity. These data and their comparison with structural data of related glucosidases and galactosidases are used for a more general discussion on the structure-function relationships in this sub-group of GH1 enzymes. Atomic coordinates of Gan1D-wild-type (WT)-P1, Gan1D-WT-C2, Gan1D-E170Q, Gan1D-WT-Gal6P, Gan1D-WT-Glc6P, and Gan1D-E170Q-Cell6P have been deposited in the Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank, under accession codes 5OKB, 5OKJ/5OKH, 5OKA/5OK7, 5OKQ/5OKK, 5OKS/5OKR, and 5OKG/5OKE, respectively.


  • Organizational Affiliation

    Institute of Chemistry, The Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Israel.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Putative 6-phospho-beta-galactobiosidase
A, B, C, D
485Geobacillus stearothermophilusMutation(s): 1 
Gene Names: gan1D
EC: 3.2.1.85
UniProt
Find proteins for W8QF82 (Geobacillus stearothermophilus)
Explore W8QF82 
Go to UniProtKB:  W8QF82
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupW8QF82
Sequence Annotations
Expand
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
6-O-phosphono-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose
E, F
2N/A
Glycosylation Resources
GlyTouCan:  G15380AW
GlyCosmos:  G15380AW
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
BG6
Query on BG6

Download Ideal Coordinates CCD File 
G [auth A],
N [auth B]
6-O-phosphono-beta-D-glucopyranose
C6 H13 O9 P
NBSCHQHZLSJFNQ-VFUOTHLCSA-N
GOL
Query on GOL

Download Ideal Coordinates CCD File 
H [auth A]
I [auth A]
J [auth A]
K [auth A]
L [auth A]
H [auth A],
I [auth A],
J [auth A],
K [auth A],
L [auth A],
O [auth B],
P [auth B],
Q [auth C],
R [auth C],
S [auth C],
T [auth C],
V [auth D]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
IMD
Query on IMD

Download Ideal Coordinates CCD File 
M [auth A],
U [auth C],
W [auth D]
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.31 Å
  • R-Value Free: 0.155 
  • R-Value Work: 0.133 
  • R-Value Observed: 0.133 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 101.599α = 90
b = 97.48β = 97.66
c = 105.269γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
iMOSFLMdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-10-18
    Type: Initial release
  • Version 1.1: 2017-10-25
    Changes: Database references
  • Version 1.2: 2017-11-01
    Changes: Database references
  • Version 1.3: 2017-11-29
    Changes: Database references
  • Version 1.4: 2017-12-06
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2024-01-17
    Changes: Data collection, Database references, Refinement description, Structure summary