6TP8

Substrate protein interactions in the limbus region of the catalytic site of Candida antarctica Lipase B


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.164 

wwPDB Validation   3D Report Full Report



Literature

Principles of lipid-enzyme interactions in the limbus region of the catalytic site of Candida antarctica Lipase B.

Silvestrini, L.Cianci, M.

(2020) Int J Biol Macromol 158: 358-363

  • DOI: 10.1016/j.ijbiomac.2020.04.061
  • Primary Citation of Related Structures:  
    6TP8

  • PubMed Abstract: 
  • Lipases (E.C. 3.1.1.3) are ubiquitous hydrolases for the carboxyl ester bond of water-insoluble substrates such as triacylglycerols and phospholipids. Candida antarctica Lipase B (CALB) acts in aqueous as well as in low-water media, thus being of con ...

    Lipases (E.C. 3.1.1.3) are ubiquitous hydrolases for the carboxyl ester bond of water-insoluble substrates such as triacylglycerols and phospholipids. Candida antarctica Lipase B (CALB) acts in aqueous as well as in low-water media, thus being of considerable biochemical significance with high interest also for its industrial applications. The hydrolysis reaction follows a two-step mechanism, or 'interfacial activation', with adsorption of the enzyme to a heterogeneous interface and subsequent enhancement of the lipolytic activity. Once positioned within the catalytic triad, substrates are then hydrolysed, and products released. However, the intermediate steps of substrate transfer from the lipidic-aqueous phase to the enzyme surface and then down to the catalytic site are still unclear. By inhibiting CALB with ethyl phosphonate and incubating with glyceryl tributyrate (2,3-di(butanoyloxy)propyl butanoate), the crystal structure of the lipid-enzyme complex, at 1.55 Å resolution, shows the tributyrin in the limbus region of active site. The substrate is found 10 Å above the catalytic Ser, with the glycerol backbone pre-aligned for further processing by key interactions via an extended water network with α-helix10 and α-helix5. The findings offer new elements to elucidate the mechanism of substrate recognition, transfer and catalysis of Candida antarctica Lipase B (CALB) and lipases in general.


    Organizational Affiliation

    Department of Agricultural, Food and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy. Electronic address: m.cianci@univpm.it.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Lipase BABC317Moesziomyces antarcticusMutation(s): 0 
EC: 3.1.1.3
Find proteins for P41365 (Pseudozyma antarctica)
Explore P41365 
Go to UniProtKB:  P41365
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
D, E, F
2 N-Glycosylation Oligosaccharides Interaction
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NTK
Query on NTK

Download Ideal Coordinates CCD File 
A, C
2,3-di(butanoyloxy)propyl butanoate
C15 H26 O6
UYXTWWCETRIEDR-UHFFFAOYSA-N
 Ligand Interaction
DEP
Query on DEP

Download Ideal Coordinates CCD File 
A, B, C
DIETHYL PHOSPHONATE
C4 H11 O3 P
MJUJXFBTEFXVKU-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.164 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 89.426α = 90
b = 156.654β = 90
c = 138.084γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2020-05-20
    Type: Initial release
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary