Genomic comparison of archaeal conjugative plasmids from Sulfolobus

Autor: Bo Greve, Susanne Jensen, Kim Brügger, Wolfram Zillig, Roger A. Garrett
Jazyk: angličtina
Rok vydání: 2004
Předmět:
Zdroj: Archaea, Vol 1, Iss 4, Pp 231-239 (2004)
Druh dokumentu: article
ISSN: 1472-3646
1472-3654
DOI: 10.1155/2004/151926
Popis: All of the known self-transmissable plasmids of the Archaea have been found in the genus Sulfolobus. To gain more insight into archaeal conjugative processes, four newly isolated self-transmissable plasmids, pKEF9, pHVE14, pARN3 and pARN4, were sequenced and subjected to a comparative sequence analysis with two earlier sequenced plasmids, pNOB8 and pING1. The analyses revealed three conserved and functionally distinct sections in the genomes. Section A is considered to encode the main components of the conjugative apparatus, where two genes show low but significant sequence similarity to sections of genes encoding bacterial conjugative proteins. A putative origin of replication is located in section B, which is highly conserved in sequence and contains several perfect and imperfect direct and inverted repeats. Further downstream, in section C, an operon encoding six to nine smaller proteins is implicated in the initiation and regulation of replication. Each plasmid carries an integrase gene of the type that does not partition on integration, and there is strong evidence for their integration into host chromosomes, where they may facilitate intercellular exchange of chromosomal genes. Two plasmids contain hexameric short regularly spaced repeats (SRSR), which have been implicated in plasmid maintenance, and each plasmid carries multiple recombination motifs, concentrated in the variable regions, which likely provide sites for genomic rearrangements.
Databáze: Directory of Open Access Journals
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