title: The polyhydroxyalkanoate genes of a stress resistant Antarctic Pseudomonas are situated within a genomic island.
abstract: Pseudomonas sp. 14-3 is an Antarctic bacterium that shows high stress resistance in association with high polyhydroxybutyrate (PHB) production. In this paper genes involved in PHB biosynthesis (phaRBAC) were found within a genomic island named pha-GI. Numerous mobile elements or proteins associated with them, such as an integrase, insertion sequences, a bacterial group II intron, a complete Type I protein secretion system and IncP plasmid-related proteins were detected among the 28 ORFs identified in this large genetic element (32.3kb). The G+C distribution was not homogeneous, likely reflecting a mosaic structure that contains regions from diverse origins. pha-GI has strong similarities with genomic islands found in diverse Proteobacteria, including Burkholderiales species and Azotobacter vinelandii. The G+C content, phylogeny inference and codon usage analysis showed that the phaBAC cluster itself has a complex mosaic structure and indicated that the phaB and phaC genes were acquired by horizontal transfer, probably derived from Burkholderiales. These results describe for the first time a pha cluster located within a genomic island, and suggest that horizontal transfer of pha genes is a mechanism of adaptability to stress conditions such as those found in the extreme Antarctic environment.
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
authors.forename: Nicolás D
authors.initials: ND
authors.lastname: Ayub
authors.forename: M Julia
authors.initials: MJ
authors.lastname: Pettinari
authors.forename: Beatriz S
authors.initials: BS
authors.lastname: Méndez
authors.forename: Nancy I
authors.initials: NI
authors.lastname: López
mesh_terms: D000217:Acyltransferases / Q000235:genetics*; D000864:Antarctic Regions; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001482:Base Composition; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D005798:Genes, Bacterial; D044404:Genomic Islands; D006885:Hydroxybutyrates / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis / Q000235:genetics*; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D006885:Hydroxybutyrates; D054813:Polyhydroxyalkanoates; D012097:Repressor Proteins; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase