Genome streamlining in a cosmopolitan oceanic bacterium

Science. 2005 Aug 19;309(5738):1242-5. doi: 10.1126/science.1114057.

Abstract

The SAR11 clade consists of very small, heterotrophic marine alpha-proteobacteria that are found throughout the oceans, where they account for about 25% of all microbial cells. Pelagibacter ubique, the first cultured member of this clade, has the smallest genome and encodes the smallest number of predicted open reading frames known for a free-living microorganism. In contrast to parasitic bacteria and archaea with small genomes, P. ubique has complete biosynthetic pathways for all 20 amino acids and all but a few cofactors. P. ubique has no pseudogenes, introns, transposons, extrachromosomal elements, or inteins; few paralogs; and the shortest intergenic spacers yet observed for any cell.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alphaproteobacteria / classification
  • Alphaproteobacteria / genetics*
  • Alphaproteobacteria / isolation & purification
  • Alphaproteobacteria / physiology
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Base Composition
  • Biological Evolution
  • Carbon / metabolism
  • Computational Biology
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • DNA, Intergenic
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial
  • Genome, Bacterial*
  • Membrane Transport Proteins / genetics
  • Membrane Transport Proteins / metabolism
  • Molecular Sequence Data
  • Oceans and Seas
  • Phosphates / metabolism
  • Phylogeny
  • Seawater / microbiology*
  • Selection, Genetic
  • Sigma Factor / genetics
  • Thymidylate Synthase / genetics

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • DNA, Intergenic
  • Membrane Transport Proteins
  • Phosphates
  • Sigma Factor
  • Carbon
  • Thymidylate Synthase

Associated data

  • GENBANK/CP000084