The chromosomal DNA of Streptomyces lividans 66 is linear

Complete genome sequence of the erythromycin-producing bacterium Saccharopolyspora erythraea NRRL23338

“…1 online). No evidence was found, from our sequence analysis, for the presence of terminal inverted repeat sequences, genes encoding termini-associated proteins or any other features of previously described linear streptomycete genomes [16][17][18] . Unlike S. coelicolor and S. avermitilis, S. erythraea also has genes resembling both xerC (SACE_2322, SACE_6041) and xerD (SACE_2295, SACE_3643, SACE_5095, SACE_5242), which together comprise a site-specific recombination system for resolving dimeric circular chromosomes.…”

Telomeres of the linear chromosomes of Lyme disease spirochaetes: nucleotide sequence and possible exchange with linear plasmid telomeres

“…The Streptomyces plasmids and chromosomes have specific proteins covalently attached to the 5Ј termini of both DNA strands (reviewed by Meinhardt et al, 1990;Sakaguchi, 1990;Lin et al, 1993;Redenbach et al, 1996), and there are large inverted repeats at the ends of the Streptomycete chromosomes (24-210 kbp repeats) and plasmids (0.04-80 kbp repeats) (Chen, 1996). The few linear Borrelia plasmids that have been studied have covalently closed hairpin ends, with only an imperfect 19 bp inverted repeat at their termini (Barbour and Garon, 1987;Hinnebusch et al, 1990;Kitten and Barbour, 1990;Zhang et al, 1997).…”

Chromosomal Circularization inStreptomyces griseusby Nonhomologous Recombination of Deletion Ends

“…Filamentous soil bacteria, Streptomyces, are unusual in carrying an 8-9 Mb linear chromosome: [1][2][3][4][5][6][7] the genome project for Streptomyces coelicolor A3(2), a model strain for Streptomyces genetics, has been recently completed. 8) Streptomyces species are also known to frequently have linear plasmids, which range from 12 to 1700 kb in size.…”

“…The last phenomenon may be an intermediate state to reach â nal stable state. Chromosomal circularization in Streptomyces waŝ rst indicated by detection of a macrorestriction fusion fragment in deletion mutants of Streptomyces lividans 1,13) and Streptomyces ambofaciens. 4) It waŝ nally conˆrmed in Streptomyces griseus by cloning and sequencing of the fusion junctions of the circularized chromosomes.…”