Characterization of Streptomyces plasmid-phage pFP4 and its evolutionary implications

摘要: Abstract Autonomous-replicating plasmid pFP4 of Streptomyces sp. FR1 isolated from a heavy metal-contaminated land was cloned and sequenced. Surprisingly, the 40,949-bp contains cluster 20 genes, resembling these chromosome-integrated prophages SPB78 scabiei 87.22. Plasmid could transfer by conjugation replication locus, iteron/ repA / repB , identified. The filtered culture infect both cured to form plaques, also six out 13 strains same land, but failed plaques on other seven source all ten species different sources. phage particles were observed transmission electron microscopy. Major structural proteins (capsid, portal tail, etc.) virions encoded twelve genes. DNA contained 3′ protruding cohesive ends 9-nt. represents novel plasmid-phage.