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Analysis of a genome fragment of a deep‐sea uncultivated Group II euryarchaeote containing 16S rDNA, a spectinomycin‐like operon and several energy metabolism genes
Author(s) -
Moreira David,
RodríguezValera Francisco,
LópezGarcía Purificación
Publication year - 2004
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2004.00644.x
Subject(s) - biology , operon , genetics , crenarchaeota , ribosomal protein , ribosomal rna , gene , genome , 16s ribosomal rna , ribosome , escherichia coli , rna
Summary We have sequenced and analysed a 39.5 kbp genome fragment of a marine Group II euryarchaeote identified in a metagenomic library of 500 m deep plankton at the Antarctic Polar Front. The clone contains a 16S rRNA gene that is separated from the 23S rRNA gene in the genome. This appears to be a trait shared by Thermoplasmatales and Group II euryarchaeota. This genome fragment exhibits a compact organization, including a few overlapping genes in the canonical spectinomycin‐like ( spc ) operon for ribosomal proteins that is immediately upstream the 16S rDNA. Most open reading frames (ORFs) encoded proteins involved in housekeeping processes and, as expected, exhibited a phylogenetic distribution congruent with that of the 16S rRNA. A considerable number of proteins with predicted transmembrane helices was identified. Among those, two proteins encoded by genes likely forming an operon appear to be part of a membrane terminal electron transport chain. One of these proteins has an unusual domain arrangement including ferredoxin, flavodoxin and one succinate dehydrogenase/fumarate reductase subunit. These proteins probably constitute a new succinate dehydrogenase‐like oxidoreductase involved in what could be a novel pathway for energy metabolism in Group II euryarchaeota.