4LYQ

Crystal Structure of Glycoside Hydrolase Family 5 Mannosidase from Rhizomucor miehei, E202A mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.163 
  • R-Value Work: 0.125 
  • R-Value Observed: 0.127 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural insights into the substrate specificity and transglycosylation activity of a fungal glycoside hydrolase family 5 beta-mannosidase.

Zhou, P.Liu, Y.Yan, Q.Chen, Z.Qin, Z.Jiang, Z.

(2014) Acta Crystallogr D Biol Crystallogr 70: 2970-2982

  • DOI: 10.1107/S1399004714019762
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • β-Mannosidases are exo-acting glycoside hydrolases (GHs) that catalyse the removal of the nonreducing end β-D-mannose from manno-oligosaccharides or mannoside-substituted molecules. They play important roles in fundamental biological processes and al ...

    β-Mannosidases are exo-acting glycoside hydrolases (GHs) that catalyse the removal of the nonreducing end β-D-mannose from manno-oligosaccharides or mannoside-substituted molecules. They play important roles in fundamental biological processes and also have potential applications in various industries. In this study, the first fungal GH family 5 β-mannosidase (RmMan5B) from Rhizomucor miehei was functionally and structurally characterized. RmMan5B exhibited a much higher activity against manno-oligosaccharides than against p-nitrophenyl β-D-mannopyranoside (pNPM) and had a transglycosylation activity which transferred mannosyl residues to sugars such as fructose. To investigate its substrate specificity and transglycosylation activity, crystal structures of RmMan5B and of its inactive E202A mutant in complex with mannobiose, mannotriose and mannosyl-fructose were determined at resolutions of 1.3, 2.6, 2.0 and 2.4 Å, respectively. In addition, the crystal structure of R. miehei β-mannanase (RmMan5A) was determined at a resolution of 2.3 Å. Both RmMan5A and RmMan5B adopt the (β/α)8-barrel architecture, which is globally similar to the other members of GH family 5. However, RmMan5B shows several differences in the loop around the active site. The extended loop between strand β8 and helix α8 (residues 354-392) forms a `double' steric barrier to `block' the substrate-binding cleft at the end of the -1 subsite. Trp119, Asn260 and Glu380 in the β-mannosidase, which are involved in hydrogen-bond contacts with the -1 mannose, might be essential for exo catalytic activity. Moreover, the structure of RmMan5B in complex with mannosyl-fructose has provided evidence for the interactions between the β-mannosidase and D-fructofuranose. Overall, the present study not only helps in understanding the catalytic mechanism of GH family 5 β-mannosidases, but also provides a basis for further enzymatic engineering of β-mannosidases and β-mannanases.


    Organizational Affiliation

    Department of Biotechnology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, People's Republic of China.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Exo-beta-1,4-mannosidase
A
449Rhizomucor mieheiMutation(s): 0 
EC: 3.2.1.25
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download CCD File 
A
4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
 Ligand Interaction
MAN
Query on MAN

Download CCD File 
A
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
BMA
Query on BMA

Download CCD File 
A
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
TRS
Query on TRS

Download CCD File 
A
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.163 
  • R-Value Work: 0.125 
  • R-Value Observed: 0.127 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 131.173α = 90
b = 76.549β = 113.36
c = 54.836γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
PHENIXmodel building
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-08-06
    Type: Initial release
  • Version 1.1: 2014-11-26
    Changes: Database references