An Acetyl Xylan Esterase (Est2A) from the Rumen Bacterium Butyrivibrio proteoclasticus.

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.208 

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This is version 1.2 of the entry. See complete history


Structure and function of an acetyl xylan esterase (Est2A) from the rumen bacterium Butyrivibrio proteoclasticus.

Till, M.Goldstone, D.C.Attwood, G.T.Moon, C.D.Kelly, W.J.Arcus, V.L.

(2013) Proteins 81: 911-917

  • DOI: https://doi.org/10.1002/prot.24254
  • Primary Citation of Related Structures:  
    3U37, 4DEV

  • PubMed Abstract: 

    Butyrivibrio proteoclasticus is a significant component of the microbial population of the rumen of dairy cattle. It is a xylan-degrading organism whose genome encodes a large number of open reading frames annotated as fiber-degrading enzymes. We have determined the three-dimensional structure of Est2A, an acetyl xylan esterase from B. proteoclasticus, at 2.1 Å resolution, along with the structure of an inactive mutant (H351A) at 2.0 Å resolution. The structure reveals two domains-a C-terminal SGNH domain and an N-terminal jelly-roll domain typical of CE2 family structures. The structures are accompanied by experimentally determined enzymatic parameters against two model substrates, para-nitrophenyl acetate and para-nitrophenyl butyrate. The suite of fiber-degrading enzymes produced by B. proteoclasticus provides a rich source of new enzymes of potential use in industrial settings.

  • Organizational Affiliation

    Department of Biological Sciences, University of Waikato, Hamilton, New Zealand.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Acetyl-xylan esterase Est2A
A, B, C, D, E
A, B, C, D, E, F, G, H
408Butyrivibrio proteoclasticus B316Mutation(s): 0 
Gene Names: est2Abpr_I2939
Find proteins for E0RVY7 (Butyrivibrio proteoclasticus (strain ATCC 51982 / DSM 14932 / B316))
Explore E0RVY7 
Go to UniProtKB:  E0RVY7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupE0RVY7
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on GOL

Download Ideal Coordinates CCD File 
C3 H8 O3
Query on ACY

Download Ideal Coordinates CCD File 
I [auth A]
J [auth B]
L [auth C]
M [auth D]
N [auth E]
I [auth A],
J [auth B],
L [auth C],
M [auth D],
N [auth E],
O [auth F],
P [auth F],
Q [auth G],
R [auth H],
S [auth H]
C2 H4 O2
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.208 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 96.128α = 99.8
b = 90.282β = 90.21
c = 99.175γ = 92.56
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-02-13
    Type: Initial release
  • Version 1.1: 2013-04-17
    Changes: Database references
  • Version 1.2: 2024-02-28
    Changes: Data collection, Database references, Derived calculations, Refinement description