4AY7

methyltransferase from Methanosarcina mazei


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.163 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of the Corrinoid:Coenzyme M Methyltransferase Mtaa from Methanosarcina Mazei

Hoeppner, A.Thomas, F.Rueppel, A.Hensel, R.Blankenfeldt, W.Bayer, P.Faust, A.

(2012) Acta Crystallogr.,Sect.D 68: 1549

  • DOI: 10.1107/S090744491203853X
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The zinc-containing corrinoid:coenzyme M methyltransferase MtaA is part of the methanol-coenzyme M-methyltransferase complex of Methanosarcina mazei. The whole complex consists of three subunits: MtaA, MtaB and MtaC. The MtaB-MtaC complex catalyses t ...

    The zinc-containing corrinoid:coenzyme M methyltransferase MtaA is part of the methanol-coenzyme M-methyltransferase complex of Methanosarcina mazei. The whole complex consists of three subunits: MtaA, MtaB and MtaC. The MtaB-MtaC complex catalyses the cleavage of methanol (bound to MtaB) and the transfer of the methyl group onto the cobalt of cob(I)alamin (bound to MtaC). The MtaA-MtaC complex catalyses methyl transfer from methyl-cob(III)alamin (bound to MtaC) to coenzyme M (bound to MtaA). The crystal structure of the MtaB-MtaC complex from M. barkeri has previously been determined. Here, the crystal structures of MtaA from M. mazei in a substrate-free but Zn(2+)-bound state and in complex with Zn(2+) and coenzyme M (HS-CoM) are reported at resolutions of 1.8 and 2.1 Å, respectively. A search for homologous proteins revealed that MtaA exhibits 23% sequence identity to human uroporphyrinogen III decarboxylase, which has also the highest structural similarity (r.m.s.d. of 2.03 Å for 306 aligned amino acids). The main structural feature of MtaA is a TIM-barrel-like fold, which is also found in all other zinc enzymes that catalyse thiol-group alkylation. The active site of MtaA is situated at the narrow bottom of a funnel such that the thiolate group of HS-CoM points towards the Zn(2+) ion. The Zn(2+) ion in the active site of MtaA is coordinated tetrahedrally via His240, Cys242 and Cys319. In the substrate-free form the fourth ligand is Glu263. Binding of HS-CoM leads to exchange of the O-ligand of Glu263 for the S-ligand of HS-CoM with inversion of the zinc geometry. The interface between MtaA and MtaC for transfer of the methyl group from MtaC-bound methylcobalamin is most likely to be formed by the core complex of MtaB-MtaC and the N-terminal segment (a long loop containing three α-helices and a β-hairpin) of MtaA, which is not part of the TIM-barrel core structure of MtaA.


    Organizational Affiliation

    Structural and Medicinal Biochemistry, Centre of Medical Biotechnology (ZMB), University of Duisburg-Essen, Campus Essen, 45117 Essen, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
METHYLCOBALAMIN\: COENZYME M METHYLTRANSFERASE
A, B
348Methanosarcina mazei (strain ATCC BAA-159 / DSM 3647 / Goe1 / Go1 / JCM 11833 / OCM 88)Mutation(s): 0 
Gene Names: mtaA
Find proteins for Q8PXZ6 (Methanosarcina mazei (strain ATCC BAA-159 / DSM 3647 / Goe1 / Go1 / JCM 11833 / OCM 88))
Go to UniProtKB:  Q8PXZ6
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CSD
Query on CSD
A, B
L-PEPTIDE LINKINGC3 H7 N O4 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.163 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 44.209α = 90.00
b = 167.419β = 117.36
c = 45.849γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
REFMACrefinement
SCALAdata scaling
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-10-31
    Type: Initial release
  • Version 1.1: 2012-11-07
    Type: Database references
  • Version 1.2: 2014-11-05
    Type: Atomic model, Derived calculations, Non-polymer description, Other, Structure summary