4RV9

Crystal structure of MtmC in complex with SAH


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.203 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Insight into MtmC, a Bifunctional Ketoreductase-Methyltransferase Involved in the Assembly of the Mithramycin Trisaccharide Chain.

Chen, J.M.Hou, C.Wang, G.Tsodikov, O.V.Rohr, J.

(2015) Biochemistry 54: 2481-2489

  • DOI: 10.1021/bi501462g
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • More and more post-PKS tailoring enzymes are recognized as being multifunctional and codependent on other tailoring enzymes. One of the recently discovered intriguing examples is MtmC, a bifunctional TDP-4-keto-d-olivose ketoreductase-methyltransfera ...

    More and more post-PKS tailoring enzymes are recognized as being multifunctional and codependent on other tailoring enzymes. One of the recently discovered intriguing examples is MtmC, a bifunctional TDP-4-keto-d-olivose ketoreductase-methyltransferase, which-in codependence with glycosyltransferase MtmGIV-is a key contributor to the biosynthesis of the critical trisaccharide chain of the antitumor antibiotic mithramycin (MTM), produced by Streptomyces argillaceus. We report crystal structures of three binary complexes of MtmC with its methylation cosubstrate SAM, its coproduct SAH, and a nucleotide TDP as well as crystal structures of two ternary complexes, MtmC-SAH-TDP-4-keto-d-olivose and MtmC-SAM-TDP, in the range of 2.2-2.7 Å resolution. The structures reveal general and sugar-specific recognition and catalytic structural features of MtmC. Depending on the catalytic function that is conducted by MtmC, it must bind either NADPH or SAM in the same cofactor binding pocket. A tyrosine residue (Tyr79) appears as a lid covering the sugar moiety of the substrate during the methyl transfer reaction. This residue swings out of the active site by ~180° in the absence of the substrate. This unique conformational change likely serves to release the methylated product and, possibly, to open the active site for binding the bulkier cosubstrate NADPH prior to the reduction reaction.


    Organizational Affiliation

    Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536-0596, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
D-mycarose 3-C-methyltransferase
A
426Streptomyces argillaceusMutation(s): 0 
Gene Names: mtmC
Find proteins for Q194Q4 (Streptomyces argillaceus)
Go to UniProtKB:  Q194Q4
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

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A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

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A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

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A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
SAH
Query on SAH

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Download CCD File 
A
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CSO
Query on CSO
A
L-PEPTIDE LINKINGC3 H7 N O3 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.203 
  • Space Group: I 41 2 2
Unit Cell:
Length (Å)Angle (°)
a = 134.245α = 90.00
b = 134.245β = 90.00
c = 130.010γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-02-04
    Type: Initial release
  • Version 1.1: 2015-03-18
    Type: Database references
  • Version 1.2: 2015-05-13
    Type: Database references