9K7C | pdb_00009k7c

Crystal structure of GH57 family amylopullulanase from Aquifex aeolicus mutant E256Q in complex with maltopentaose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 
    0.226 (Depositor), 0.227 (DCC) 
  • R-Value Work: 
    0.189 (Depositor), 0.194 (DCC) 
  • R-Value Observed: 
    0.191 (Depositor) 

Starting Model: in silico
View more details

wwPDB Validation 3D Report Full Report

Validation slider image for 9K7C

This is version 1.0 of the entry. See complete history

Literature

The crystal structure of GH57 family amylopullulanase reveals its dual binding pockets sharing the same catalytic dyad.

Zhu, Z.Wang, W.Li, M.Xu, Q.Zhou, H.Huang, L.Wang, Q.Yu, F.

(2025) Commun Biol 8: 806-806

  • DOI: https://doi.org/10.1038/s42003-025-08192-8
  • Primary Citation Related Structures: 
    8ZYI, 9IHT, 9IHU, 9IHV, 9IHW, 9IHX, 9II0, 9II1, 9K7C, 9K7D

  • PubMed Abstract: 

    Glycoside Hydrolase Family 57 (GH57) amylopullulanase is a thermophilic endoamylase capable of hydrolyzing both α-1,4 and α-1,6-glycosidic bonds, demonstrating significant potential for one-step starch saccharification in industrial applications. However, the mechanisms underlying the dual catalytic activities of GH57 family amylopullulanase remain poorly understood. In this study, we report the first crystal structures of a GH57 amylopullulanase from Aquifex aeolicus (AaApu) in complex with oligosaccharides containing both α-1,4 and α-1,6 glycosidic bonds. Our structural analysis reveals that GH57 amylopullulanase features dual binding pockets arranged in a "Y"-shaped configuration, which accommodates branched-chain starches. The dual binding pockets share a common catalytic dyad composed of Glu256 and Asp352. Notably, unlike the typical retaining mechanism observed in many glycoside hydrolases, the distance between the catalytic residues in GH57 amylopullulanase is significantly larger (approximately 7 Å). This study provides critical insights into the structural basis of GH57 amylopullulanase activity and offers a foundation for the rational engineering of these enzymes for industrial applications.


  • Organizational Affiliation
    • Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China.

Macromolecule Content 

  • Total Structure Weight: 234.09 kDa 
  • Atom Count: 17,542 
  • Modeled Residue Count: 1,905 
  • Deposited Residue Count: 1,908 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Glycoside hydrolase family 57 N-terminal domain-containing protein
A, B, C, D
477Aquifex aeolicus VF5Mutation(s): 1 
Gene Names: aq_720
UniProt
Find proteins for O66934 (Aquifex aeolicus (strain VF5))
Explore O66934 
Go to UniProtKB:  O66934
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO66934
Sequence Annotations
Expand
Reference Sequence

Oligosaccharides

Help  
Entity ID: 2
MoleculeChains Length2D Diagram GlycosylationD Interactions
alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose
E, I
3N/A
Glycosylation Resources
GlyTouCan: G96370VA
GlyCosmos: G96370VA
GlyGen: G96370VA
Entity ID: 3
MoleculeChains Length2D Diagram GlycosylationD Interactions
alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose
F, H, J, K
5N/A
Glycosylation Resources
GlyTouCan: G50146AM
GlyCosmos: G50146AM
Entity ID: 4
MoleculeChains Length2D Diagram GlycosylationD Interactions
alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose
G
4N/A
Glycosylation Resources
GlyTouCan: G87171PZ
GlyCosmos: G87171PZ
GlyGen: G87171PZ

Small Molecules

Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
GOL

Query on GOL



Download:Ideal Coordinates CCD File
L [auth B]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N

Biologically Interesting Molecules (External Reference) 

1 Unique

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free:  0.226 (Depositor), 0.227 (DCC) 
  • R-Value Work:  0.189 (Depositor), 0.194 (DCC) 
  • R-Value Observed: 0.191 (Depositor) 
Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 40.82α = 83.98
b = 61.373β = 89.08
c = 195.564γ = 89.18
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
XDSdata reduction
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Other government--

Revision History  (Full details and data files)

  • Version 1.0: 2025-06-04
    Type: Initial release