Crystal structure of fusion protein of MsrA and MsrB

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.239 

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This is version 1.3 of the entry. See complete history


Structural and Kinetic Analysis of an MsrA-MsrB Fusion Protein from Streptococcus pneumoniae

Kim, Y.K.Shin, Y.J.Lee, W.-H.Kim, H.-Y.Hwang, K.Y.

(2009) Mol Microbiol 72: 699-709

  • DOI: https://doi.org/10.1111/j.1365-2958.2009.06680.x
  • Primary Citation of Related Structures:  
    3E0M, 3E0O

  • PubMed Abstract: 

    Methionine sulphoxide reductases (Msr) catalyse the reduction of oxidized methionine to methionine. These enzymes are divided into two classes, MsrA and MsrB, according to substrate specificity. Although most MsrA and MsrB exist as separate enzymes, in some bacteria these two enzymes are fused to form a single polypeptide (MsrAB). Here, we report the first crystal structure of MsrAB from Streptococcus pneumoniae (SpMsrAB) at 2.4 A resolution. SpMsrAB consists of an N-terminal MsrA domain, a C-terminal MsrB domain and a linker. The linker is composed of 13 residues and contains one 3(10)-helix and several hydrogen bonds interacting with both MsrA and MsrB domains. Interestingly, our structure includes the MsrB domain complexed with an SHMAEI hexa-peptide that is the N-terminal region of neighbouring MsrA domain. A kinetic analysis showed that the apparent K(m) of SpMsrAB for the R-form-substrate was 20-fold lower than that for the S-form substrate, indicating that the MsrB domain had a much higher affinity for the substrate than the MsrA domain. Our study reveals the first structure of the MsrAB by providing insights into the formation of a disulphide bridge in the MsrB, the structure of the linker region, and the distinct structural nature of active site of each MsrA and MsrB domain.

  • Organizational Affiliation

    Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Peptide methionine sulfoxide reductase msrA/msrB 1
A, B, C, D
313Streptococcus pneumoniaeMutation(s): 1 
Gene Names: msrAB1exp3msrASP_1359
EC: (PDB Primary Data), (PDB Primary Data)
Find proteins for P0A3Q9 (Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4))
Explore P0A3Q9 
Go to UniProtKB:  P0A3Q9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0A3Q9
Sequence Annotations
  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Short peptide SHMAEI
E, F, G
6N/AMutation(s): 0 
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.239 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 158.521α = 90
b = 165.489β = 90
c = 77.281γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2021-11-10
    Changes: Database references
  • Version 1.3: 2024-05-29
    Changes: Data collection