4QQS

Crystal structure of a thermostable family-43 glycoside hydrolase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.1 Å
  • R-Value Free: 0.145 
  • R-Value Work: 0.122 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

High-resolution crystal structure of a polyextreme GH43 glycosidase from Halothermothrix orenii with alpha-L-arabinofuranosidase activity.

Hassan, N.Kori, L.D.Gandini, R.Patel, B.K.Divne, C.Tan, T.C.

(2015) Acta Crystallogr F Struct Biol Commun 71: 338-345

  • DOI: 10.1107/S2053230X15003337

  • PubMed Abstract: 
  • A gene from the heterotrophic, halothermophilic marine bacterium Halothermothrix orenii has been cloned and overexpressed in Escherichia coli. This gene encodes the only glycoside hydrolase of family 43 (GH43) produced by H. orenii. The crystal struc ...

    A gene from the heterotrophic, halothermophilic marine bacterium Halothermothrix orenii has been cloned and overexpressed in Escherichia coli. This gene encodes the only glycoside hydrolase of family 43 (GH43) produced by H. orenii. The crystal structure of the H. orenii glycosidase was determined by molecular replacement and refined at 1.10 Å resolution. As for other GH43 members, the enzyme folds as a five-bladed β-propeller. The structure features a metal-binding site on the propeller axis, near the active site. Based on thermal denaturation data, the H. orenii glycosidase depends on divalent cations in combination with high salt for optimal thermal stability against unfolding. A maximum melting temperature of 76°C was observed in the presence of 4 M NaCl and Mn(2+) at pH 6.5. The gene encoding the H. orenii GH43 enzyme has previously been annotated as a putative α-L-arabinofuranosidase. Activity was detected with p-nitrophenyl-α-L-arabinofuranoside as a substrate, and therefore the name HoAraf43 was suggested for the enzyme. In agreement with the conditions for optimal thermal stability against unfolding, the highest arabinofuranosidase activity was obtained in the presence of 4 M NaCl and Mn(2+) at pH 6.5, giving a specific activity of 20-36 µmol min(-1) mg(-1). The active site is structurally distinct from those of other GH43 members, including arabinanases, arabinofuranosidases and xylanases. This probably reflects the special requirements for degrading the unique biomass available in highly saline aqueous ecosystems, such as halophilic algae and halophytes. The amino-acid distribution of HoAraf43 has similarities to those of mesophiles, thermophiles and halophiles, but also has unique features, for example more hydrophobic amino acids on the surface and fewer buried charged residues.


    Organizational Affiliation

    School of Biotechnology, KTH Royal Institute of Technology, Stockholm, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glycoside hydrolase family 43
A, B
315Halothermothrix orenii (strain H 168 / OCM 544 / DSM 9562)
Find proteins for B8CZV1 (Halothermothrix orenii (strain H 168 / OCM 544 / DSM 9562))
Go to UniProtKB:  B8CZV1
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

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

Download SDF File 
Download CCD File 
A, B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.1 Å
  • R-Value Free: 0.145 
  • R-Value Work: 0.122 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 44.133α = 90.00
b = 73.882β = 94.27
c = 87.520γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
PHENIXmodel building
PHENIXrefinement
XSCALEdata scaling
PHENIXphasing
GDAdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-03-11
    Type: Initial release
  • Version 1.1: 2015-03-25
    Type: Database references