title: Molecular characterization of the leucine cluster in Buchnera sp. strain PSY, a primary endosymbiont of the aphid Pemphigus spyrothecae.
abstract: Buchnera strains from most aphid subfamilies studied to date have been found to carry the leucine gene cluster (leuA, -B, -C, and -D) on a plasmid, an organization unique among bacteria. Here, however, we demonstrate a classical chromosomal location of the cluster in Buchnera sp. strain PSY from the aphid Pemphigus spyrothecae (subfamily Pemphiginae). The genes that flank leuABCD in Buchnera sp. strain PSY appear to be adjacent in the genome of Buchnera sp. strain APS, a strain carrying a leucine plasmid. We propose that the presence of a leucine plasmid predates the diversification of symbiotic Buchnera and that the chromosomal location observed in Buchnera sp. strain PSY arose by a transfer of the leucine genes from a plasmid to the chromosome.
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, València 46071, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Sabater-Muñoz
authors.forename: Laura
authors.initials: L
authors.lastname: Gómez-Valero
authors.forename: Roeland C H J
authors.initials: RC
authors.lastname: van Ham
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Silva
authors.forename: Amparo
authors.initials: A
authors.lastname: Latorre
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D020635:Buchnera / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D005784:Gene Amplification; D006836:Hydro-Lyases; D007930:Leucine / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010392:Pemphigus / Q000382:microbiology*; D013559:Symbiosis / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006836:Hydro-Lyases; C094205:LeuC protein, bacteria; C087070:leuD protein, Bacteria; D007930:Leucine