1. Analysis of the chromosome sequence of the legume symbiont Sinorhizobium meliloti strain 1021
- Author
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Daniel Portetelle, Clotilde Renard, Frédéric Ampe, Stéphanie Gloux, André Goffeau, Micheline Vandenbol, Frédérique Barloy-Hubler, David Masuy, P. Boistard, Anke Becker, Bénédicte Purnelle, Ernö Kiss, Thomas Pohl, Jérôme Gouzy, Patricia Thebault, Francis Galibert, Stéphane Dréano, Stefan Weidner, Thérèse Godrie, Ulf Ramsperger, Jacques Batut, Alfred Pühler, Edouard Cadieu, Valerie Lelaure, G. Bothe, Daniel Kahn, Marc Boutry, Delphine Capela, Bioinformatique, phylogénie et génomique évolutive (BPGE), Département PEGASE [LBBE] (PEGASE), Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), and Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
DNA Replication ,DNA, Bacterial ,[SDV.OT]Life Sciences [q-bio]/Other [q-bio.OT] ,Chromosomes, Artificial, Bacterial ,DNA Repair ,Transcription, Genetic ,Molecular Sequence Data ,Genome ,03 medical and health sciences ,Complete sequence ,Bacterial Proteins ,Cell Movement ,Gene Duplication ,Replicon ,Symbiosis ,Gene ,030304 developmental biology ,2. Zero hunger ,Genetics ,0303 health sciences ,Sinorhizobium meliloti ,Multidisciplinary ,Plants, Medicinal ,biology ,Virulence ,030306 microbiology ,Nucleic acid sequence ,Fabaceae ,Sequence Analysis, DNA ,Chromosomes, Bacterial ,Biological Sciences ,biology.organism_classification ,Housekeeping gene ,Peptide transport ,Genes, Bacterial ,DNA, Circular ,Carrier Proteins ,Energy Metabolism ,Cell Division ,Autre (Sciences du Vivant) ,Signal Transduction - Abstract
Sinorhizobium meliloti is an α-proteobacterium that forms agronomically important N 2 -fixing root nodules in legumes. We report here the complete sequence of the largest constituent of its genome, a 62.7% GC-rich 3,654,135-bp circular chromosome. Annotation allowed assignment of a function to 59% of the 3,341 predicted protein-coding ORFs, the rest exhibiting partial, weak, or no similarity with any known sequence. Unexpectedly, the level of reiteration within this replicon is low, with only two genes duplicated with more than 90% nucleotide sequence identity, transposon elements accounting for 2.2% of the sequence, and a few hundred short repeated palindromic motifs (RIME1, RIME2, and C) widespread over the chromosome. Three regions with a significantly lower GC content are most likely of external origin. Detailed annotation revealed that this replicon contains all housekeeping genes except two essential genes that are located on pSymB. Amino acid/peptide transport and degradation and sugar metabolism appear as two major features of the S. meliloti chromosome. The presence in this replicon of a large number of nucleotide cyclases with a peculiar structure, as well as of genes homologous to virulence determinants of animal and plant pathogens, opens perspectives in the study of this bacterium both as a free-living soil microorganism and as a plant symbiont.
- Published
- 2001