4A0G

Structure of bifunctional DAPA aminotransferase-DTB synthetase from Arabidopsis thaliana in its apo form.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.177 
  • R-Value Observed: 0.180 

wwPDB Validation 3D Report Full Report



Literature

Biochemical and Structural Characterization of the Arabidopsis Bifunctional Enzyme Dethiobiotin Synthetase-Diaminopelargonic Acid Aminotransferase: Evidence for Substrate Channeling in Biotin Synthesis.

Cobessi, D.Dumas, R.Pautre, V.Meinguet, C.Ferrer, J.L.Alban, C.

(2012) Plant Cell 24: 1608

  • DOI: 10.1105/tpc.112.097675
  • Primary Citation of Related Structures:  
    4A0R, 4A0F, 4A0G, 4A0H

  • PubMed Abstract: 
  • Diaminopelargonic acid aminotransferase (DAPA-AT) and dethiobiotin synthetase (DTBS) catalyze the antepenultimate and the penultimate steps, respectively, of biotin synthesis. Whereas DAPA-AT and DTBS are encoded by distinct genes in bacteria, in bio ...

    Diaminopelargonic acid aminotransferase (DAPA-AT) and dethiobiotin synthetase (DTBS) catalyze the antepenultimate and the penultimate steps, respectively, of biotin synthesis. Whereas DAPA-AT and DTBS are encoded by distinct genes in bacteria, in biotin-synthesizing eukaryotes (plants and most fungi), both activities are carried out by a single enzyme encoded by a bifunctional gene originating from the fusion of prokaryotic monofunctional ancestor genes. In few angiosperms, including Arabidopsis thaliana, this chimeric gene (named BIO3-BIO1) also produces a bicistronic transcript potentially encoding separate monofunctional proteins that can be produced following an alternative splicing mechanism. The functional significance of the occurrence of a bifunctional enzyme in biotin synthesis pathway in eukaryotes and the relative implication of each of the potential enzyme forms (bifunctional versus monofunctional) in the plant biotin pathway are unknown. In this study, we demonstrate that the BIO3-BIO1 fusion protein is the sole protein form produced by the BIO3-BIO1 locus in Arabidopsis. The enzyme catalyzes both DAPA-AT and DTBS reactions in vitro and is targeted to mitochondria in vivo. Our biochemical and kinetic characterizations of the pure recombinant enzyme show that in the course of the reaction, the DAPA intermediate is directly transferred from the DAPA-AT active site to the DTBS active site. Analysis of several structures of the enzyme crystallized in complex with and without its ligands reveals key structural elements involved for acquisition of bifunctionality and brings, together with mutagenesis experiments, additional evidences for substrate channeling.


    Organizational Affiliation

    Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, Université Joseph Fourier, Institut de Biologie Structurale Jean-Pierre Ebel, F-38027 Grenoble Cedex 1, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ADENOSYLMETHIONINE-8-AMINO-7-OXONONANOATE AMINOTRANSFERASEABCD831Arabidopsis thalianaMutation(s): 0 
Gene Names: BIO3-BIO1BIO1BIO3At5g57590MUA2.17/MUA2.18
EC: 6.3.3.3 (UniProt), 2.6.1.62 (UniProt)
Find proteins for B0F481 (Arabidopsis thaliana)
Explore B0F481 
Go to UniProtKB:  B0F481
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLP
Query on PLP

Download CCD File 
A, B, C, D
PYRIDOXAL-5'-PHOSPHATE
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MG
Query on MG

Download CCD File 
B, D
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.177 
  • R-Value Observed: 0.180 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.442α = 99.96
b = 80.066β = 107.12
c = 136.939γ = 97.25
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-06-13
    Type: Initial release