Structure of the MoaA Arg17/266/268/Ala triple mutant

Experimental Data Snapshot

  • Resolution: 2.25 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Binding of 5'-GTP to the C-terminal FeS cluster of the radical S-adenosylmethionine enzyme MoaA provides insights into its mechanism

Haenzelmann, P.Schindelin, H.

(2006) Proc Natl Acad Sci U S A 103: 6829-6834

  • DOI: https://doi.org/10.1073/pnas.0510711103
  • Primary Citation of Related Structures:  
    2FB2, 2FB3

  • PubMed Abstract: 

    The first step in molybdenum cofactor biosynthesis, the conversion of 5'-GTP to precursor Z, an oxygen-sensitive tetrahydropyranopterin is catalyzed by the S-adenosylmethionine (SAM)-dependent enzyme MoaA and the accessory protein MoaC. This reaction involves the radical-initiated intramolecular rearrangement of the guanine C8 atom. MoaA harbors an N-terminal [4Fe-4S] cluster, which is involved in the reductive cleavage of SAM and generates a 5'-deoxyadenosyl radical (5'-dA*), and a C-terminal [4Fe-4S] cluster presumably involved in substrate binding and/or activation. Biochemical studies identified residues involved in 5'-GTP binding and the determinants of nucleotide specificity. The crystal structure of MoaA in complex with 5'-GTP confirms the biochemical data and provides valuable insights into the subsequent radical reaction. MoaA binds 5'-GTP with high affinity and interacts through its C-terminal [4Fe-4S] cluster with the guanine N1 and N2 atoms, in a yet uncharacterized binding mode. The tightly anchored triphosphate moiety prevents the escape of radical intermediates. This structure also visualizes the L-Met and 5'-dA cleavage products of SAM. Rotation of the 5'-dA ribose and/or conformational changes of the guanosine are proposed to bring the 5'-deoxyadenosyl radical into close proximity of either the ribose C2' and C3' or the guanine C8 carbon atoms leading to hydrogen abstraction.

  • Organizational Affiliation

    Department of Biochemistry and Center for Structural Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA. petra@csb.sunysb.edu

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Molybdenum cofactor biosynthesis protein A
A, B
340Staphylococcus aureusMutation(s): 3 
Gene Names: moaA
Find proteins for P69848 (Staphylococcus aureus (strain NCTC 8325 / PS 47))
Explore P69848 
Go to UniProtKB:  P69848
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP69848
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on SAM

Download Ideal Coordinates CCD File 
D [auth A],
H [auth B]
C15 H22 N6 O5 S
Query on SF4

Download Ideal Coordinates CCD File 
E [auth A],
F [auth A],
I [auth B],
J [auth B]
Fe4 S4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth A],
G [auth B]
O4 S
Experimental Data & Validation

Experimental Data

  • Resolution: 2.25 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.965α = 90
b = 101.293β = 90
c = 190.127γ = 90
Software Package:
Software NamePurpose
CBASSdata collection
SCALEPACKdata scaling
FFTmodel building

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-05-09
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Refinement description, Version format compliance
  • Version 1.3: 2021-10-20
    Changes: Database references, Derived calculations