Biological Assembly 1  

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

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 53.7 kDa 
• Atom Count: 4,193 
• Modelled Residue Count: 452 
• Deposited Residue Count: 454 
• Unique protein chains: 1

 5A2A

Crystal Structure of Anoxybacillus Alpha-amylase Provides Insights into a New Glycosyl Hydrolase Subclass

• PDB DOI:  https://doi.org/10.2210/pdb5A2A/pdb

• Classification: HYDROLASE
• Organism(s): Anoxybacillus ayderensis
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2015-05-16 Released: 2016-03-30 
• Deposition Author(s): Ng, C.L., Chai, K.P., Othman, N.F., Teh, A.H., Ho, K.L., Chan, K.G., Goh, K.M.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.236 
• R-Value Work: 0.177 
• R-Value Observed: 0.180 

Literature

Crystal Structure of Anoxybacillus Alpha-Amylase Provides Insights Into Maltose Binding of a New Glycosyl Hydrolase Subclass.

Chai, K.P., Othman, N.F.B., Teh, A., Ho, K.L., Chan, K., Shamsir, M.S., Goh, K.M., Ng, C.L.

(2016) Sci Rep 6: 23126

• PubMed: 26975884 
• DOI: https://doi.org/10.1038/srep23126
• Primary Citation of Related Structures:  
  5A2A, 5A2B, 5A2C


• PubMed Abstract: 
  

A new subfamily of glycosyl hydrolase family GH13 was recently proposed for α-amylases from Anoxybacillus species (ASKA and ADTA), Geobacillus thermoleovorans (GTA, Pizzo, and GtamyII), Bacillus aquimaris (BaqA), and 95 other putative protein homologues. To understand this new GH13 subfamily, we report crystal structures of truncated ASKA (TASKA). ASKA is a thermostable enzyme capable of producing high levels of maltose. Unlike GTA, biochemical analysis showed that Ca(2+) ion supplementation enhances the catalytic activities of ASKA and TASKA. The crystal structures reveal the presence of four Ca(2+) ion binding sites, with three of these binding sites are highly conserved among Anoxybacillus α-amylases. This work provides structural insights into this new GH13 subfamily both in the apo form and in complex with maltose. Furthermore, structural comparison of TASKA and GTA provides an overview of the conformational changes accompanying maltose binding at each subsite.

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Organizational Affiliation: 

Universiti Kebangsaan Malaysia, Institute of Systems Biology, 43600 UKM Bangi, Selangor, Malaysia.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
APO FORM OF ANOXYBACILLUS ALPHA-AMYLASES	A	454	Anoxybacillus ayderensis	Mutation(s): 0  EC: 3.2.1.1
UniProt
Find proteins for I1VWH9 (Anoxybacillus ayderensis) Explore I1VWH9  Go to UniProtKB:  I1VWH9

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ACT	B [auth A], C [auth A]	ACETATE ION C2 H3 O2 QTBSBXVTEAMEQO-UHFFFAOYSA-M
CA	D [auth A], E [auth A], F [auth A], G [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.236 
• R-Value Work: 0.177 
• R-Value Observed: 0.180 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 61.429	α = 90
b = 63.443	β = 90
c = 122.758	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
XDS	data reduction
XSCALE	data scaling
PHASER	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2016-03-30 
Deposition Author(s): Ng, C.L., Chai, K.P., Othman, N.F., Teh, A.H., Ho, K.L., Chan, K.G., Goh, K.M.

Revision History  

• Version 1.0: 2016-03-30
  Type: Initial release