title: The 160-kilobase genome of the bacterial endosymbiont Carsonella.
abstract: Previous studies have suggested that the minimal cellular genome could be as small as 400 kilobases. Here, we report the complete genome sequence of the psyllid symbiont Carsonella ruddii, which consists of a circular chromosome of 159,662 base pairs, averaging 16.5% GC content. It is by far the smallest and most AT-rich bacterial genome yet characterized. The genome has a high coding density (97%) with many overlapping genes and reduced gene length. Genes for translation and amino acid biosynthesis are relatively well represented, but numerous genes considered essential for life are missing, suggesting that Carsonella may have achieved organelle-like status.
authors.affiliation: Environmental Molecular Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan. bachi@email.arizona.edu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakabachi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamashita
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Toh
authors.forename: Hajime
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Helen E
authors.initials: HE
authors.lastname: Dunbar
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Moran
authors.forename: Masahira
authors.initials: M
authors.lastname: Hattori
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis; D000818:Animals; D001482:Base Composition; D002876:Chromosomes, Bacterial; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020563:Gammaproteobacteria / Q000235:genetics* / Q000502:physiology; D005798:Genes, Bacterial; D005807:Genes, Overlapping; D020459:Genes, rRNA; D016680:Genome, Bacterial; D006430:Hemiptera / Q000235:genetics / Q000382:microbiology* / Q000502:physiology; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012343:RNA, Transfer / Q000235:genetics; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D000596:Amino Acids; D004269:DNA, Bacterial; D012343:RNA, Transfer