Molecular cloning and mapping of a deletion derivative of the plasmid Rts1
1981; Elsevier BV; Volume: 6; Issue: 2 Linguagem: Inglês
10.1016/0147-619x(81)90068-8
ISSN1095-9890
AutoresYoshiro Terawaki, Yuko Kobayashi, Hideki Matsumoto, Yoshiyuki Kamio,
Tópico(s)Bacteriophages and microbial interactions
ResumoAbstract The plasmid pTW20 is a deletion derivative of the kanamycin resistance plasmid Rts1. By digesting pTW20 DNA with Eco RI endonuclease six fragments were generated, and each was cloned in the vector plasmid pACYC184. These cloned Eco RI fragments were further digested with various endonucleases, and the cleavage map of pTW20 was constructed. A Sal I fragment (1.5 Md) in E1 (the largest Eco RI fragment; 11.5 Md) contained the genes kan (kanamycin resistance) and puv (uv sensitization of host). An electron microscopy study of a Bam HI fragment containing kan revealed the presence of a transposon-like structure in the fragment. The smallest Eco RI fragment E6 (2.0 Md) was capable of autonomous replication in a polA host, indicating that E6 contained replication genes of pTW20. These genes were found to be located on a 1.1-Md Hin dIII fragment in E6. Two incompatibility genes were identified on the pTW20 genome, one located on each of the fragments E6 and E5 (3.5 Md), and expressed T incompatibility independently. The nature of the temperature sensitivity of pTW20 was discussed.
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