title: The plant oncogene rolD encodes a functional ornithine cyclodeaminase.
abstract: The plant oncogene rolD stimulates the reproductive phase transition in plants. We define here the function of its gene product. We show that the RolD protein bears sequence homology with ornithine cyclodeaminase, an uncommon enzyme of specialized-niche eubacteria and archaea that catalyzes the unusual NAD(+)-dependent conversion of ornithine to proline. To confirm the prediction of the bioinformatic analysis, the RolD protein was expressed in Escherichia coli and purified. An ornithine-dependent NAD(+) reduction that can be ascribed only to ornithine cyclodeaminase (OCD) activity was detected both in bacterial extracts containing RolD and in assays on the purified RolD protein. Furthermore, OCD activity was observed in soluble extracts from plants overexpressing rolD. The role of rolD in plant pathogenesis and its effect on plant reproductive development are discussed in light of the newly demonstrated enzymatic activity of its gene product.
authors.affiliation: Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Trovato
authors.forename: B
authors.initials: B
authors.lastname: Maras
authors.forename: F
authors.initials: F
authors.lastname: Linhares
authors.forename: P
authors.initials: P
authors.lastname: Costantino
mesh_terms: D000595:Amino Acid Sequence; D000642:Ammonia-Lyases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002384:Catalysis; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D009857:Oncogenes; D010944:Plants / Q000201:enzymology / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D011994:Recombinant Proteins; D000642:Ammonia-Lyases; C021914:ornithine cyclodeaminase