Genome sequence of the cyanobacterium Prochlorococcus marinus SS120, a nearly minimal oxyphototrophic genome

• DOI: 10.1073/pnas.1733211100
• Publication Date: 2003-08-19T16:56:21Z
• Authors: Alexis Dufresne; Marcel Salanoubat; Frédéric Partensky; François Artiguenave; Ilka M. Axmann; Valérie Barbe; Simone Duprat; Michael Y. Galperin; Eugene V. Koonin; Florence Le Gall; Kira S. Makarova; Martin Ostrowski; Sophie Oztas; Catherine Robert; Igor B. Rogozin; David J. Scanlan; Nicole Tandeau de...; Jean Weissenbach; Patrick Wincker; Yuri I. Wolf; Wolfgang R. Hess
• Keywords: Prochlorococcus; Genome size; GC-content; Bacterial genome size

Prochlorococcus marinus , the dominant photosynthetic organism in ocean, is found two main ecological forms: high-light-adapted genotypes upper part of water column and low-light-adapted at bottom illuminated layer. P. SS120, complete genome sequence reported here, an extremely form. The SS120 composed a single circular chromosome 1,751,080 bp with average G+C content 36.4%. It contains 1,884 predicted protein-coding genes size 825 bp, rRNA operon, 40 tRNA genes. Together 1.66-Mbp MED4, one smallest genomes known to date. lacks many that are involved photosynthesis, DNA repair, solute uptake, intermediary metabolism, motility, phototaxis, other functions conserved among cyanobacteria. Systems signal transduction environmental stress response show particularly drastic reduction number components, even taking into account small genome. In contrast, housekeeping genes, which encode enzymes amino acid, nucleotide, cofactor, cell wall biosynthesis, all present. Because its remarkable compactness, might approximate minimal gene complement organism.