title: Functional and phylogenetic analysis of a plant-inducible oligoribonuclease (orn) gene from an indigenous Pseudomonas plasmid.
abstract: Application of a promoter-trapping strategy to identify plant-inducible genes carried on an indigenous Pseudomonas plasmid, pQBR103, revealed the presence of a putative oligoribonuclease (orn) gene that encodes a highly conserved 3' to 5' exoribonuclease specific for small oligoribonucleotides. The deduced amino acid sequence of the plasmid-derived orn (orn(pl)) showed three conserved motifs characteristic of Orn from both prokaryotes and eukaryotes. Deletion of orn(pl) generated no observable phenotype, but inactivation of the chromosomal copy caused slow growth in Pseudomonas putida KT2440. This defect was fully restored by complementation with orn from Escherichia coli (orn(E.coli)). Plasmid-derived orn(pl) was capable of partially complementing the P. putida orn mutant, demonstrating functionality of orn(pl). Phylogenetic analysis showed that plasmid-encoded Orn was distinct from Orn encoded by the chromosome of proteobacteria. A survey of orn(pl) from related Pseudomonas plasmids showed a sporadic distribution but no sequence diversity. These data suggest that the orn(pl) was acquired by pQBR103 in a single gene-transfer event: the donor is unknown, but is unlikely to be a member of the Proteobacteria.
authors.affiliation: Centre for Ecology and Hydrology NERC, Mansfield Road, Oxford OX1 3SR, UK.|School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.|Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Xue-Xian
authors.initials: XX
authors.lastname: Zhang
authors.affiliation: Centre for Ecology and Hydrology NERC, Mansfield Road, Oxford OX1 3SR, UK.
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Lilley
authors.affiliation: Centre for Ecology and Hydrology NERC, Mansfield Road, Oxford OX1 3SR, UK.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Bailey
authors.affiliation: School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.|Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Rainey
mesh_terms: D000595:Amino Acid Sequence; D027461:Beta vulgaris / Q000382:microbiology*; D002876:Chromosomes, Bacterial / Q000235:genetics; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D005095:Exoribonucleases / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D010944:Plants / Q000382:microbiology; D010957:Plasmids; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D011549:Pseudomonas / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D016958:Pseudomonas putida / Q000235:genetics; D012639:Seeds / Q000382:microbiology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D005095:Exoribonucleases; C094587:oligoribonuclease