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Published on: November 8, 2019
Characterization of Nocardia plasmid pXT107
Hai-Yang Xia1, Yong-Qiang Tian, Ran Zhang
1College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Acta Biochimica Et Biophysica Sinica
|September 6, 2006
Summary
A novel plasmid, pXT107, was identified in Nocardia sp. 107. Its rep gene enabled replication in Nocardia, but not Streptomyces, advancing actinomycete plasmid research.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Actinomycetes, including Nocardia, Rhodococcus, and Streptomyces, are Gram-positive bacteria with high G+C content.
- Plasmids play crucial roles in bacterial genetics and adaptation.
- Understanding novel plasmids aids in genetic manipulation and understanding bacterial diversity.
Purpose of the Study:
- To characterize a newly identified plasmid, pXT107, from Nocardia sp. 107.
- To determine the replication mechanism and host range of pXT107.
- To explore the utility of pXT107 in constructing shuttle vectors for Nocardia.
Main Methods:
- Complete nucleotide sequencing of plasmid pXT107.
- Bioinformatic analysis of plasmid genes and replication origins.
- Construction and testing of an Escherichia coli-Nocardia shuttle plasmid (pHAQ22) containing the pXT107 rep gene.
Main Results:
- Plasmid pXT107 is a small circular plasmid (4335 bp) with 65% G+C content.
- pXT107 encodes a replication extragenic palindromic (Rep) protein and six hypothetical proteins.
- The replication origins of pXT107 are characteristic of rolling-circle-replication plasmids.
- The pXT107 rep gene facilitated replication in Nocardia but not in Streptomyces.
Conclusions:
- pXT107 represents one of the smallest plasmids identified in Nocardia.
- The replication machinery of pXT107 is similar to other known rolling-circle-replication plasmids.
- The rep gene of pXT107 is a valuable tool for developing Nocardia-specific vectors.
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