Biological Assembly 1  

 3D View: Structure | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 21.41 kDa 
• Atom Count: 1830 
• Modelled Residue Count: 207 
• Deposited Residue Count: 207 
• Unique protein chains: 1

1G66

ACETYLXYLAN ESTERASE AT 0.90 ANGSTROM RESOLUTION

• DOI: 10.2210/pdb1G66/pdb

• Classification: HYDROLASE
• Organism(s): Talaromyces purpureogenus
• Mutation(s): No 


• Deposited: 2000-11-03 Released: 2001-01-17 
• Deposition Author(s): Ghosh, D., Sawicki, M., Lala, P., Erman, M., Pangborn, W., Eyzaguirre, J., Gutierrez, R., Jornvall, H., Thiel, D.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 0.90 Å
• R-Value Free: 0.132 
• R-Value Work: 0.107 
• R-Value Observed: 0.107 

Literature

Multiple conformations of catalytic serine and histidine in acetylxylan esterase at 0.90 A.

Ghosh, D., Sawicki, M., Lala, P., Erman, M., Pangborn, W., Eyzaguirre, J., Gutierrez, R., Jornvall, H., Thiel, D.J.

(2001) J Biol Chem 276: 11159-11166

• PubMed: 11134051 
• DOI: 10.1074/jbc.M008831200
• Primary Citation of Related Structures:  
  1G66


• PubMed Abstract: 
  

Acetylxylan esterase (AXEII; 207 amino acids) from Penicillium purpurogenum has substrate specificities toward acetate esters of d-xylopyranose residues in xylan and belongs to a new class of alpha/beta hydrolases. The crystal structure of AXEII has been determined by single isomorphous replacement and anomalous scattering, and refined at 0.90- and 1.10-A resolutions with data collected at 85 K and 295 K, respectively. The tertiary structure consists of a doubly wound alpha/beta sandwich, having a central six-stranded parallel beta-sheet flanked by two parallel alpha-helices on each side. The catalytic residues Ser(90), His(187), and Asp(175) are located at the C-terminal end of the sheet, an exposed region of the molecule. The serine and histidine side chains in the 295 K structure show the frequently observed conformations in which Ser(90) is trans and the hydroxyl group is in the plane of the imidazole ring of His(187). However, the structure at 85 K displays an additional conformation in which Ser(90) side-chain hydroxyl is away from the plane of the imidazole ring of His(187). The His(187) side chain forms a hydrogen bond with a sulfate ion and adopts an altered conformation. The only other known hydrolase that has a similar tertiary structure is Fusarium solani cutinase. The exposed nature of the catalytic triad suggests that AXEII is a pure esterase, i.e. an alpha/beta hydrolase with specificity for nonlipidic polar substrates.

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Related Citations: 

• Determination of a protein structure by iodination: the structure of iodinated acetylxylan esterase
  Ghosh, D., Erman, M., Sawicki, M., Lala, P., Weeks, D.R., Li, N., Pangborn, W., Thiel, D.J., Jornvall, H., Gutierrez, R., Eyzaguirre, J.
  (1999) Acta Crystallogr D Biol Crystallogr 55: 779

• Characterization of crystals of P. purpurogenum acetyl xylan esterase from high resolution X-ray diffraction
  (1996) Proteins 24: 523

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Organizational Affiliation: 

Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203, USA. [e-mail]

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ACETYL XYLAN ESTERASE II	A	207	Talaromyces purpureogenus	Mutation(s): 0  Gene Names: axe-2, axeII EC: 3.1.1.6 (PDB Primary Data), 3.1.1.72 (UniProt)
Find proteins for O59893 (Talaromyces purpureogenus) Explore O59893  Go to UniProtKB:  O59893

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SO4	A	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L
GOL	A	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 0.90 Å
• R-Value Free: 0.132 
• R-Value Work: 0.107 
• R-Value Observed: 0.107 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 34.541	α = 90
b = 59.898	β = 90
c = 71.392	γ = 90

Software Package:

Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
PHASES	phasing
SHELXL-97	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2000-11-03 
• Released Date: 2001-01-17 
Deposition Author(s): Ghosh, D., Sawicki, M., Lala, P., Erman, M., Pangborn, W., Eyzaguirre, J., Gutierrez, R., Jornvall, H., Thiel, D.J.

Revision History  

• Version 1.0: 2001-01-17
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Non-polymer description, Version format compliance