1PJQ

Structure and function of CysG, the multifunctional methyltransferase/dehydrogenase/ferrochelatase for siroheme synthesis

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.235 

wwPDB Validation 3D Report Full Report


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

Literature

CysG structure reveals tetrapyrrole-binding features and novel regulation of siroheme biosynthesis.

Stroupe, M.E., Leech, H.K., Daniels, D.S., Warren, M.J., Getzoff, E.D.

(2003) Nat.Struct.Mol.Biol. 10: 1064-1073

  • DOI: 10.1038/nsb1007
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Sulfur metabolism depends on the iron-containing porphinoid siroheme. In Salmonella enterica, the S-adenosyl-L-methionine (SAM)-dependent bismethyltransferase, dehydrogenase and ferrochelatase, CysG, synthesizes siroheme from uroporphyrinogen III (ur ...

    Sulfur metabolism depends on the iron-containing porphinoid siroheme. In Salmonella enterica, the S-adenosyl-L-methionine (SAM)-dependent bismethyltransferase, dehydrogenase and ferrochelatase, CysG, synthesizes siroheme from uroporphyrinogen III (uro'gen III). The reactions mediated by CysG encompass two branchpoint intermediates in tetrapyrrole biosynthesis, diverting flux first from protoporphyrin IX biosynthesis and then from cobalamin (vitamin B(12)) biosynthesis. We determined the first structure of this multifunctional siroheme synthase by X-ray crystallography. CysG is a homodimeric gene fusion product containing two structurally independent modules: a bismethyltransferase and a dual-function dehydrogenase-chelatase. The methyltransferase active site is a deep groove with a hydrophobic patch surrounded by hydrogen bond donors. This asymmetric arrangement of amino acids may be important in directing substrate binding. Notably, our structure shows that CysG is a phosphoprotein. From mutational analysis of the post-translationally modified serine, we suggest a conserved role for phosphorylation in inhibiting dehydrogenase activity and modulating metabolic flux between siroheme and cobalamin pathways.

    Organizational Affiliation: 

    Department of Molecular Biology and Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Siroheme synthase
A, B
457Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 0 
Gene Names: cysG
Find proteins for P25924 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P25924
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT
Download SDF File 
Download CCD File 
A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
SAH
Query on SAH
Download SDF File 
Download CCD File 
B
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N
 Ligand Interaction
PGE
Query on PGE
Download SDF File 
Download CCD File 
A
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
A, B
L-PEPTIDE LINKINGC3 H8 N O6 PSER
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.235 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 60.734α = 90.00
b = 121.493β = 90.00
c = 130.790γ = 90.00
Software Package:
Software NamePurpose
SHARPphasing
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-12-02
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2014-11-12
    Type: Structure summary