6SEA

Cold-adapted beta-D-galactosidase from Arthrobacter sp. 32cB mutant E441Q in complex with lactose bound in deep mode


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.87 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.182 

Starting Model: experimental
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This is version 2.1 of the entry. See complete history


Literature

Active Site Architecture and Reaction Mechanism Determination of Cold Adapted beta-d-galactosidase fromArthrobactersp. 32cB.

Rutkiewicz, M.Bujacz, A.Wanarska, M.Wierzbicka-Wos, A.Cieslinski, H.

(2019) Int J Mol Sci 20

  • DOI: https://doi.org/10.3390/ijms20174301
  • Primary Citation of Related Structures:  
    6SE8, 6SE9, 6SEA, 6SEB, 6SEC, 6SED

  • PubMed Abstract: 

    Arth βDG is a dimeric, cold-adapted β-d-galactosidase that exhibits high hydrolytic and transglycosylation activity. A series of crystal structures of its wild form, as well as its Arth βDG_E441Q mutein complexes with ligands were obtained in order to describe the mode of its action. The Arth βDG_E441Q mutein is an inactive form of the enzyme designed to enable observation of enzyme interaction with its substrate. The resulting three-dimensional structures of complexes: Arth βDG_E441Q/LACs and Arth βDG/IPTG (ligand bound in shallow mode) and structures of complexes Arth βDG_E441Q/LACd, Arth βDG/ONPG (ligands bound in deep mode), and galactose Arth βDG/GAL and their analysis enabled structural characterization of the hydrolysis reaction mechanism. Furthermore, comparative analysis with mesophilic analogs revealed the most striking differences in catalysis mechanisms. The key role in substrate transfer from shallow to deep binding mode involves rotation of the F581 side chain. It is worth noting that the 10-aa loop restricting access to the active site in mesophilic GH2 βDGs, in Arth βDG is moved outward. This facilitates access of substrate to active site. Such a permanent exposure of the entrance to the active site may be a key factor for improved turnover rate of the cold adapted enzyme and thus a structural feature related to its cold adaptation.


  • Organizational Affiliation

    Institute of Technical Biochemistry, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-galactosidase1,010Arthrobacter sp. 32cBMutation(s): 1 
EC: 3.2.1.23
UniProt
Find proteins for A0A023UGN9 (Arthrobacter sp. 32cB)
Go to UniProtKB:  A0A023UGN9
Sequence Annotations
Expand
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-galactopyranose-(1-4)-beta-D-glucopyranose
B
2N/A
Glycosylation Resources
GlyTouCan:  G84224TW
GlyCosmos:  G84224TW
GlyGen:  G84224TW
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
GAL (Subject of Investigation/LOI)
Query on GAL

Download Ideal Coordinates CCD File 
L [auth A],
M [auth A]
beta-D-galactopyranose
C6 H12 O6
WQZGKKKJIJFFOK-FPRJBGLDSA-N
ACT
Query on ACT

Download Ideal Coordinates CCD File 
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A]
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
NA
Query on NA

Download Ideal Coordinates CCD File 
C [auth A],
D [auth A],
E [auth A],
F [auth A]
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 2
IDChains NameType/Class2D Diagram3D Interactions
PRD_900004
Query on PRD_900004
B
beta-lactoseOligosaccharide / Nutrient
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.87 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.182 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 138.613α = 90
b = 138.613β = 90
c = 127.347γ = 120
Software Package:
Software NamePurpose
XSCALEdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Polish National Science CentrePoland2016/21/B/ST5/00555

Revision History  (Full details and data files)

  • Version 1.0: 2019-09-11
    Type: Initial release
  • Version 1.1: 2019-09-18
    Changes: Data collection, Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Author supporting evidence, Data collection, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2024-01-24
    Changes: Data collection, Database references, Refinement description, Structure summary