3NDI

X-ray Structure of a C-3'-Methyltransferase in Complex with S-adenosylmethionine and dTMP

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history. 


Literature

Molecular Architecture of a C-3'-Methyltransferase Involved in the Biosynthesis of d-Tetronitrose.

Bruender, N.A., Thoden, J.B., Kaur, M., Avey, M.K., Holden, H.M.

(2010) Biochemistry 49: 5891-5898

  • DOI: https://doi.org/10.1021/bi100782b
  • Primary Citation of Related Structures:  
    3NDI, 3NDJ

  • PubMed Abstract: 

    S-Adenosylmethionine (SAM)-dependent methyltransferases are involved in a myriad of biological processes, including signal transduction, chromatin repair, metabolism, and biosyntheses, among others. Here we report the high-resolution structure of a novel C-3'-methyltransferase involved in the production of D-tetronitrose, an unusual sugar found attached to the antitumor agent tetrocarcin A or the antibiotic kijanimicin. Specifically, this enzyme, referred to as TcaB9 and cloned from Micromonospora chalcea, catalyzes the conversion of dTDP-3-amino-2,3,6-trideoxy-4-keto-D-glucose to dTDP-3-amino-2,3,6-trideoxy-4-keto-3-methyl-D-glucose. For this analysis, two structures were determined to 1.5 A resolution: one in which the enzyme was crystallized in the presence of SAM and dTMP and the other with the protein complexed to S-adenosylhomocysteine and its dTDP-linked sugar product. The overall fold of the monomeric enzyme can be described in terms of three domains. The N-terminal domain harbors the binding site for a zinc ion that is ligated by four cysteines. The middle domain adopts the canonical "SAM-binding" fold with a seven-stranded mixed beta-sheet flanked on either side by three alpha-helices. This domain is responsible for anchoring the SAM cofactor to the protein. Strikingly, the C-terminal domain also contains a seven-stranded beta-sheet, and it appears to be related to the middle domain by an approximate 2-fold rotational axis, thus suggesting TcaB9 arose via gene duplication. Key residues involved in sugar binding include His 181, Glu 224, His 225, and Tyr 222. Their possible roles in catalysis are discussed.

    • Organizational Affiliation: 

    Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.


Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Methyltransferase416Micromonospora chalceaMutation(s): 0 
Gene Names: tcab9
UniProt
Find proteins for B5L6K6 (Micromonospora chalcea)
Explore B5L6K6 
Go to UniProtKB:  B5L6K6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB5L6K6
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 100.963α = 90
b = 114.385β = 90
c = 37.782γ = 90
Software Package:
Software NamePurpose
PROTEUM PLUSdata collection
PHASERphasing
REFMACrefinement
SAINTdata reduction
SADABSdata scaling

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


View more in-depth experimental data
Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-06-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2024-02-21
    Changes: Data collection, Database references, Derived calculations
  • Version 1.3: 2024-04-03
    Changes: Refinement description