4RJE

Aerococcus viridans L-lactate oxidase mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.180 
  • R-Value Work: 0.152 
  • R-Value Observed: 0.153 

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Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

The Ala95-to-Gly substitution in Aerococcus viridans l-lactate oxidase revisited - structural consequences at the catalytic site and effect on reactivity with O2 and other electron acceptors.

Stoisser, T.Rainer, D.Leitgeb, S.Wilson, D.K.Nidetzky, B.

(2015) FEBS J 282: 562-578

  • DOI: 10.1111/febs.13162
  • Primary Citation of Related Structures:  
    4RJE

  • PubMed Abstract: 
  • Aerococcus viridansl-lactate oxidase (avLOX) is a biotechnologically important flavoenzyme that catalyzes the conversion of L-lactate and O₂ into pyruvate and H₂O₂. The enzymatic reaction underlies different biosensor applications of avLOX for blood L-lactate determination ...

    Aerococcus viridansl-lactate oxidase (avLOX) is a biotechnologically important flavoenzyme that catalyzes the conversion of L-lactate and O₂ into pyruvate and H₂O₂. The enzymatic reaction underlies different biosensor applications of avLOX for blood L-lactate determination. The ability of avLOX to replace O₂ with other electron acceptors such as 2,6-dichlorophenol-indophenol (DCIP) allows the possiblity of analytical and practical applications. The A95G variant of avLOX was previously shown to exhibit lowered reactivity with O₂ compared to wild-type enzyme and therefore was employed in a detailed investigation with respect to the specificity for different electron acceptor substrates. From stopped-flow experiments performed at 20 °C (pH 6.5), we determined that the A95G variant (fully reduced by L-lactate) was approximately three-fold more reactive towards DCIP (1.0 ± 0.1 × 10(6) M(-1) ·s(-1) ) than O₂, whereas avLOX wild-type under the same conditions was 14-fold more reactive towards O₂(1.8 ± 0.1 × 10(6) m(-1) ·s(-1)) than DCIP. Substituted 1,4-benzoquinones were up to five-fold better electron acceptors for reaction with L-lactate-reduced A95G variant than wild-type. A 1.65-Å crystal structure of oxidized A95G variant bound with pyruvate was determined and revealed that the steric volume created by removal of the methyl side chain of Ala95 and a slight additional shift in the main chain at position Gly95 together enable the accomodation of a new active-site water molecule within hydrogen-bond distance to the N5 of the FMN cofactor. The increased steric volume available in the active site allows the A95G variant to exhibit a similar trend with the related glycolate oxidase in electron acceptor substrate specificities, despite the latter containing an alanine at the analogous position.


    Organizational Affiliation

    Research Center Pharmaceutical Engineering, Graz, Austria; Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Lactate oxidaseA, B, C, D374Aerococcus viridansMutation(s): 5 
EC: 1.13.12.4 (PDB Primary Data), 1.1.3 (UniProt)
UniProt
Find proteins for Q44467 (Aerococcus viridans (strain ATCC 11563 / DSM 20340 / CCUG 4311 / JCM 20461 / NBRC 12219 / NCTC 8251 / M1))
Explore Q44467 
Go to UniProtKB:  Q44467
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ44467
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.180 
  • R-Value Work: 0.152 
  • R-Value Observed: 0.153 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 122.593α = 90
b = 124.355β = 124.29
c = 106.885γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
PHASERphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-12-03
    Type: Initial release
  • Version 1.1: 2014-12-10
    Changes: Database references
  • Version 1.2: 2015-03-11
    Changes: Database references