4DGK

Crystal structure of Phytoene desaturase CRTI from Pantoea ananatis

Summary for 4DGK

• Entry DOI: 10.2210/pdb4dgk/pdb
• Descriptor: Phytoene dehydrogenase, 1,2-ETHANEDIOL, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: the fad/nad(p)-binding rossmann fold, oxidoreductase
• Biological source: Pantoea ananatis
• Cellular location: Cell membrane : P21685
• Total number of polymer chains: 1
• Total formula weight: 56448.18

Authors

Schaub, P.,Yu, Q.,Gemmecker, S.,Poussin-Courmontagne, P.,Mailliot, J.,McEwen, A.G.,Ghisla, S.,Beyer, P.,Cavarelli, J. (deposition date: 2012-01-26, release date: 2012-10-10, Last modification date: 2024-02-28)

Primary citation

Schaub, P.,Yu, Q.,Gemmecker, S.,Poussin-Courmontagne, P.,Mailliot, J.,McEwen, A.G.,Ghisla, S.,Al-Babili, S.,Cavarelli, J.,Beyer, P.
On the structure and function of the phytoene desaturase CRTI from Pantoea ananatis, a membrane-peripheral and FAD-dependent oxidase/isomerase.
Plos One, 7:e39550-e39550, 2012

PubMed Abstract: CRTI-type phytoene desaturases prevailing in bacteria and fungi can form lycopene directly from phytoene while plants employ two distinct desaturases and two cis-tans isomerases for the same purpose. This property renders CRTI a valuable gene to engineer provitamin A-formation to help combat vitamin A malnutrition, such as with Golden Rice. To understand the biochemical processes involved, recombinant CRTI was produced and obtained in homogeneous form that shows high enzymatic activity with the lipophilic substrate phytoene contained in phosphatidyl-choline (PC) liposome membranes. The first crystal structure of apo-CRTI reveals that CRTI belongs to the flavoprotein superfamily comprising protoporphyrinogen IX oxidoreductase and monoamine oxidase. CRTI is a membrane-peripheral oxidoreductase which utilizes FAD as the sole redox-active cofactor. Oxygen, replaceable by quinones in its absence, is needed as the terminal electron acceptor. FAD, besides its catalytic role also displays a structural function by enabling the formation of enzymatically active CRTI membrane associates. Under anaerobic conditions the enzyme can act as a carotene cis-trans isomerase. In silico-docking experiments yielded information on substrate binding sites, potential catalytic residues and is in favor of single half-site recognition of the symmetrical C(40) hydrocarbon substrate.

PubMed: 22745782
DOI: 10.1371/journal.pone.0039550

Experimental method

X-RAY DIFFRACTION (2.35 Å)