pING Family of Conjugative Plasmids from the Extremely Thermophilic Archaeon Sulfolobus islandicus: Insights into Recombination and Conjugation in Crenarchaeota
This investigation was supported by the European Union in the framework of its Biotechnology Program project “Extremophiles as Cell Factories” and by the Novo Nordisk Foundation. K.M.S. was supported by a Marie Curie research fellowship from the European Union and a NSF-NATO postdoctoral fellowship.
Journal of Bacteriology
Thermophilic microorganisms, Microbial ecology, Plasmids -- Genetics
A novel family of conjugative plasmids from Sulfolobus comprising the active variants pING1, -4, and -6 and the functionally defective variants pING2 and -3, which require the help of an active variant for spreading, has been extensively characterized both functionally and molecularly. In view of the sparse similarity between bacterial and archaeal conjugation and the lack of a practical genetic system for Sulfolobus, we compared the functions and sequences of these variants and the previously described archaeal conjugative plasmid pNOB8 in order to identify open reading frames (ORFs) and DNA sequences that are involved in conjugative transfer and maintenance of these plasmids in Sulfolobus. The variants pING4 and -6 are reproducibly derived from pING1 in vivo by successive transpositions of an element from the Sulfolobus genome. The small defective but mobile variants pING2 and -3, which both lack a cluster of highly conserved ORFs probably involved in plasmid transfer, were shown to be formed in vivo by recombinative deletion of the larger part of the genomes of pING4 and pING6, respectively. The efﬁcient occurrence of these recombination processes is further evidence for the striking plasticity of the Sulfolobus genome.
Stedman, Kenneth M., et al. "pING family of conjugative plasmids from the extremely thermophilic archaeon Sulfolobus islandicus: insights into recombination and conjugation in Crenarchaeota." Journal of bacteriology 182.24 (2000): 7014-7020.