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Published on: March 11, 2022
[Replication and conjugation of Streptomyces small plasmid pDYM4. 3k]
Min Zhou1, Yumei Dai, Li Zhong
1Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China. zhoumin1108@gmail.com
Objective:
Streptomyces sp. X335, harboring a 4. 3-kb plasmid pDYM4.3k, was isolated from Tibet sample. Cloning, sequencing, analyzing and functional investigations of pDYM4. 3k.
Methods:
Prime walking to obtain plasmid sequence, BLAST to predict gene function, Southern hybridization to determine replication intermediates, and mating to test conjugal function of plasmid.
Results:
The complete nucleotide sequence of pDYM4. 3k consisted of 4346 bp, encoding 3 genes of which one resembled Streptomyces major conjugative gene tra and other two were with unknown functions. Experiments demonstrated that a new gene of pDYM4. 3k and its upstream c. 300 bp were required for plasmid replication. Single-stranded pDYM4. 3k as a replication intermediate was detected, indicating it rolling-cirle replication mode. pDYM4.3k could conjugal transfer among Streptomyces lividans.
Conclusion:
Streptomyces small plasmid pDYM4. 3k was able to autonomous replication and conjugal transferring.
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