Proteorhodopsin lateral gene transfer between marine planktonic Bacteria and Archaea

TY - JOUR

T1 - Proteorhodopsin lateral gene transfer between marine planktonic Bacteria and Archaea

AU - Frigaard, Niels-Ulrik

AU - Martinez, Asuncion

AU - Mincer, Tracy J

AU - DeLong, Edward F

N1 - Keywords: Archaea; Bacteria; Gene Transfer, Horizontal; Genes, Archaeal; Genes, Bacterial; Genes, rRNA; Genome; Genomic Library; Marine Biology; Molecular Sequence Data; Photic Stimulation; Phylogeny; Plankton; Rhodopsin; Seawater; Sunlight; Synteny

PY - 2006

Y1 - 2006

N2 - Planktonic Bacteria, Archaea and Eukarya reside and compete in the ocean's photic zone under the pervasive influence of light. Bacteria in this environment were recently shown to contain photoproteins called proteorhodopsins, thought to contribute to cellular energy metabolism by catalysing light-driven proton translocation across the cell membrane. So far, proteorhodopsin genes have been well documented only in proteobacteria and a few other bacterial groups. Here we report the presence and distribution of proteorhodopsin genes in Archaea affiliated with the order Thermoplasmatales, in the ocean's upper water column. The genomic context and phylogenetic relationships of the archaeal and proteobacterial proteorhodopsins indicate its probable lateral transfer between planktonic Bacteria and Archaea. About 10% of the euryarchaeotes in the photic zone contained the proteorhodopsin gene adjacent to their small-subunit ribosomal RNA. The archaeal proteorhodopsins were also found in other genomic regions, in the same or in different microbial lineages. Although euryarchaeotes were distributed throughout the water column, their proteorhodopsins were found only in the photic zone. The cosmopolitan phylogenetic distribution of proteorhodopsins reflects their significant light-dependent fitness contributions, which drive the photoprotein's lateral acquisition and retention, but constrain its dispersal to the photic zone.

AB - Planktonic Bacteria, Archaea and Eukarya reside and compete in the ocean's photic zone under the pervasive influence of light. Bacteria in this environment were recently shown to contain photoproteins called proteorhodopsins, thought to contribute to cellular energy metabolism by catalysing light-driven proton translocation across the cell membrane. So far, proteorhodopsin genes have been well documented only in proteobacteria and a few other bacterial groups. Here we report the presence and distribution of proteorhodopsin genes in Archaea affiliated with the order Thermoplasmatales, in the ocean's upper water column. The genomic context and phylogenetic relationships of the archaeal and proteobacterial proteorhodopsins indicate its probable lateral transfer between planktonic Bacteria and Archaea. About 10% of the euryarchaeotes in the photic zone contained the proteorhodopsin gene adjacent to their small-subunit ribosomal RNA. The archaeal proteorhodopsins were also found in other genomic regions, in the same or in different microbial lineages. Although euryarchaeotes were distributed throughout the water column, their proteorhodopsins were found only in the photic zone. The cosmopolitan phylogenetic distribution of proteorhodopsins reflects their significant light-dependent fitness contributions, which drive the photoprotein's lateral acquisition and retention, but constrain its dispersal to the photic zone.

U2 - 10.1038/nature04435

DO - 10.1038/nature04435

M3 - Journal article

C2 - 16482157

SN - 0028-0836

VL - 439

SP - 847

EP - 850

JO - Nature

JF - Nature

IS - 7078

ER -