Open AccessPresence of a Family of Plasmids (29 to 65 Kilobases) with a 26-Kilobase Common Region in Different Strains of the Sulfur-Oxidizing Bacterium Acidithiobacillus caldus
Author(s) -
Leonardo Joaquim van Zyl,
Shelly M. Deane,
Lilly-Ann Louw,
Douglas E. Rawlings
Publication year - 2008
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.00864-08
Subject(s) - plasmid , biology , genetics , transposable element , insertion sequence , t dna binary system , gene , genome , vector (molecular biology) , recombinant dna
Three large cryptic plasmids from different isolates of Acidithiobacillus caldus were rescued by using an in vitro transposition system that delivers a kanamycin-selectable marker and an Escherichia coli plasmid origin of replication. The largest of the plasmids, the 65-kb plasmid pTcM1, was isolated from a South African A. caldus strain, MNG. This plasmid was sequenced and compared to that of pTcF1 (39 kb, from strain "f," South Africa) and pC-SH12 (29 kb, from strain C-SH12, Australia). With the exception of a 2.7-kb insertion sequence, pC-SH12 appears to represent the DNA common to all three plasmids and includes a number of accessory genes plus the plasmid "backbone" containing the replication region. The two larger plasmids carry, in addition, a number of insertion sequences of the ISL3 family and a composite transposon related to the Tn21 subfamily containing a highly mosaic region within the borders of the inverted repeats. Genes coding for arsenic resistance, plasmid mobilization, plasmid stability, and a putative restriction-modification system occur within these mosaic regions.