Presence 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.
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.
Department of Microbiology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
Leonard J
LJ
van Zyl
Shelly M
SM
Deane
Lilly-Ann
LA
Louw
Douglas E
DE
Rawlings
D042763:Acidithiobacillus / Q000145:classification* / Q000235:genetics*; D001315:Australia; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D016366:Open Reading Frames; D010957:Plasmids / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D012093:Replicon; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D013019:South Africa; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000235:genetics
D004251:DNA Transposable Elements; D004269:DNA, Bacterial