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


This is version 1.1 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: 10.1021/bi100782b
  • Structures With Same Primary Citation

  • 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 n ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Methyltransferase
A
416Micromonospora chalceaMutation(s): 0 
Gene Names: tcab9
Find proteins for B5L6K6 (Micromonospora chalcea)
Go to UniProtKB:  B5L6K6
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAM
Query on SAM

Download CCD File 
A
S-ADENOSYLMETHIONINE
C15 H22 N6 O5 S
MEFKEPWMEQBLKI-FCKMPRQPSA-N
 Ligand Interaction
TMP
Query on TMP

Download CCD File 
A
THYMIDINE-5'-PHOSPHATE
C10 H15 N2 O8 P
GYOZYWVXFNDGLU-XLPZGREQSA-N
 Ligand Interaction
PO4
Query on PO4

Download CCD File 
A
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
ZN
Query on ZN

Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
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



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-06-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance