Tn5041-like transposons: molecular diversity, evolutionary relationships and distribution of distinct variants in environmental bacteria b bThe accession numbers for the nucleotide sequences reported in this work are given in the legends for Figs 1 F1 and 2. c cA comparison of the sequence of INT5041C with other proteins is available as supplementary data on Microbiology Online (http://mic.sgmjournals.org)

Autor:	Vadim Nikiforov, Gennady Kholodii, Zh. M. Gorlenko, Jon L. Hobman, Sofia Mindlin
Rok vydání:	2002
Předmět:	Genetics Transposable element Composite transposon biology Molecular evolution biology.protein Group II intron Restriction fragment length polymorphism Homologous recombination Integron Microbiology Transposons as a genetic tool
Zdroj:	Microbiology. 148:3569-3582
ISSN:	1465-2080 1350-0872
Popis:	A detailed study on the geographic distribution, molecular diversity and evolutionary relationships of 24 closely related variants of the Tn5041 transposon found among 182 mercury resistant environmental Gram-negative strains from the IMG-Hg Reference Collection is reported here. RFLP analysis, followed by the determination of partial DNA sequences, identified 14 distinct types of these transposons, which differed from each other by 1-7 single-event DNA polymorphisms. No polymorphisms were detected at the right arm of the transposons except an insertion of a new mobile DNA element carrying a mer operon (named the mer2 cassette) within the Tn5041 mer operon. According to the model presented here, the insertion occurred via homologous recombination with a circular form of the mer2 cassette. A total of 8 point mutations, 1 internal deletion, 2 end-involving deletions, 3 mosaic regions and 2 insertions were detected at the left arm of the transposons. The insertions were a transposon closely related to Tn21 but lacking the integron and a new group II intron (named INT5041C). Inspection of the geographic distribution of the Tn5041 variants suggested that at least three long-distance waves of dissemination of these variants had occurred, accompanied by homologous recombination between different Tn5041 lineages. Movements of circular DNAs by homologous recombination as a source of mosaic genes and new mer genes, and formation of unusual mosaics ending or beginning at the Tn5041 att site are discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::06451721887f8362f6d8748e9468394f https://doi.org/10.1099/00221287-148-11-3569 Zobrazit plný text záznamu