6NEU

FAD-dependent monooxygenase TropB from T. stipitatus R206Q variant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.193 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

Structural basis for selectivity in flavin-dependent monooxygenase-catalyzed oxidative dearomatization.

Rodriguez Benitez, A.Tweedy, S.E.Baker Dockrey, S.A.Lukowski, A.L.Wymore, T.Khare, D.Brooks 3rd, C.L.Palfey, B.A.Smith, J.L.Narayan, A.R.H.

(2019) ACS Catal 9: 3633-3640

  • DOI: https://doi.org/10.1021/acscatal.8b04575
  • Primary Citation of Related Structures:  
    6NES, 6NET, 6NEU, 6NEV

  • PubMed Abstract: 

    Biocatalytic reactions embody many features of ideal chemical transformations, including the potential for impeccable selectivity, high catalytic efficiency, mild reaction conditions and the use of environmentally benign reagents. These advantages have created a demand for biocatalysts that expand the portfolio of complexity-generating reactions available to synthetic chemists. However, the tradeoff that often exists between the substrate scope of a biocatalyst and its selectivity limits the application of enzymes in synthesis. We recently demonstrated that a flavin-dependent monooxygenase, TropB, maintains high levels of site- and stereoselectivity across a range of structurally diverse substrates. Herein, we disclose the structural basis for substrate binding in TropB, which performs a synthetically challenging asymmetric oxidative dearomatization reaction with exquisite site- and stereoselectivity across a range of phenol substrates, providing a foundation for future protein engineering and reaction development efforts. Our hypothesis for substrate binding is informed by a crystal structure of TropB and molecular dynamics simulations with the corresponding computational TropB model and is supported by experimental data. In contrast to canonical class A FAD-dependent monooxygenases in which substrates bind in a protonated form, our data indicate that the phenolate form of the substrate binds in the active site. Furthermore, the substrate position is controlled through twopoint binding of the phenolate oxygen to Arg206 and Tyr239, which are shown to have distinct and essential roles in catalysis. Arg206 is involved in the reduction of the flavin cofactor, suggesting a role in flavin dynamics. Further, QM/MM simulations reveal the interactions that govern the facial selectivity that leads to a highly enantioselective transformation. Thus, the structural origins of the high levels of site-and stereoselectivity observed in reactions of TropB across a range of substrates are elucidated, providing a foundation for future protein engineering and reaction development efforts.


  • Organizational Affiliation

    Program in Chemical Biology, University of Michigan, Ann arbor Michigan 48109.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
FAD-dependent monooxygenase tropB
A, B
447Talaromyces stipitatus ATCC 10500Mutation(s): 1 
Gene Names: tropBtsL1TSTA_117740
EC: 1
UniProt
Find proteins for B8M9J8 (Talaromyces stipitatus (strain ATCC 10500 / CBS 375.48 / QM 6759 / NRRL 1006))
Explore B8M9J8 
Go to UniProtKB:  B8M9J8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB8M9J8
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.193 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.801α = 90
b = 184.173β = 90
c = 163.52γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Cootmodel building
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM124880
National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK)United StatesDK042303

Revision History  (Full details and data files)

  • Version 1.0: 2019-08-14
    Type: Initial release
  • Version 1.1: 2019-12-25
    Changes: Author supporting evidence
  • Version 1.2: 2023-10-11
    Changes: Data collection, Database references, Refinement description