Bifunctional Methionine Sulfoxide Reductase AB (MsrAB) from Treponema denticola

Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.206 

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Essential Role of the Linker Region in the Higher Catalytic Efficiency of a Bifunctional MsrA-MsrB Fusion Protein

Han, A.R.Kim, M.J.Kwak, G.H.Son, J.Hwang, K.Y.Kim, H.Y.

(2016) Biochemistry 55: 5117-5127

  • DOI: https://doi.org/10.1021/acs.biochem.6b00544
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Many bacteria, particularly pathogens, possess methionine sulfoxide reductase A (MsrA) and B (MsrB) as a fusion form (MsrAB). However, it is not clear why they possess a fusion MsrAB form rather than the separate enzymes that exist in most organisms. In this study, we performed biochemical and kinetic analyses of MsrAB from Treponema denticola (TdMsrAB), single-domain forms (TdMsrA and TdMsrB), and catalytic Cys mutants (TdMsrAB(C11S) and TdMsrAB(C285S)). We found that the catalytic efficiency of both MsrA and MsrB increased after fusion of the domains and that the linker region (iloop) that connects TdMsrA and TdMsrB is required for the higher catalytic efficiency of TdMsrAB. We also determined the crystal structure of TdMsrAB at 2.3 Å, showing that the iloop mainly interacts with TdMsrB via hydrogen bonds. Further kinetic analysis using the iloop mutants revealed that the iloop-TdMsrB interactions are critical to MsrB and MsrA activities. We also report the structure in which an oxidized form of dithiothreitol, an in vitro reductant for MsrA and MsrB, is present in the active site of TdMsrA. Collectively, the results of this study reveal an essential role of the iloop in maintaining the higher catalytic efficiency of the MsrAB fusion enzyme and provide a better understanding of why the MsrAB enzyme exists as a fused form.

  • Organizational Affiliation

    Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University , Seoul 02841, Republic of Korea.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Peptide methionine sulfoxide reductase MsrA
A, B
325Treponema denticola ATCC 35405Mutation(s): 2 
Gene Names: msrATDE_0709
Find proteins for Q73PT7 (Treponema denticola (strain ATCC 35405 / DSM 14222 / CIP 103919 / JCM 8153 / KCTC 15104))
Explore Q73PT7 
Go to UniProtKB:  Q73PT7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ73PT7
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.30 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.206 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 144.956α = 90
b = 95.584β = 116.24
c = 81.39γ = 90
Software Package:
Software NamePurpose
HKL-2000data scaling
PHENIXmodel building

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-09-14
    Type: Initial release
  • Version 1.1: 2016-09-28
    Changes: Database references
  • Version 1.2: 2023-11-08
    Changes: Data collection, Database references, Derived calculations, Refinement description