Open AccessSequence of plasmid pGT5 from the archaeon Pyrococcus abyssi: evidence for rolling-circle replication in a hyperthermophile
Author(s) -
Gaël Erauso,
Stéphanie Marsin,
N. D. Benbouzid-Rollet,
Marie-France Baucher,
Tristan Barbeyron,
Yvan Zivanovic,
Daniël Prieur,
Patrick Forterre
Publication year - 1996
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.178.11.3232-3237.1996
Subject(s) - biology , rolling circle replication , replicon , plasmid , genetics , open reading frame , origin of replication , dna replication , archaea , dna , peptide sequence , bacteria , gene
The plasmid pGT5 (3,444 bp) from the hyperthermophilic archaeon Pyrococcus abyssi GE5 has been completely sequenced. Two major open reading frames with a good coding probability are located on the same strand and cover 85% of the total sequence. The larger open reading frame encodes a putative polypeptide which exhibits sequence similarity with Rep proteins of plasmids using the rolling-circle mechanism for replication. Upstream of this open reading frame, we have detected an 11-bp motif identical to the double-stranded origin of several bacterial plasmids that replicate via the rolling-circle mechanism. A putative single-stranded origin exhibits similarities both to bacterial primosome-dependent single-stranded initiation sites and to bacterial primase (dnaG) start sites. A single-stranded form of pGT5 corresponding to the plus strand was detected in cells of P. abyssi. These data indicate that pGT5 replicates via the rolling-circle mechanism and suggest that members of the domain Archaea contain homologs of several bacterial proteins involved in chromosomal DNA replication. Phylogenetic analysis of Rep proteins from rolling-circle replicons suggest that diverse families diverged before the separation of the domains Archaea, Bacteria, and Eucarya.