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Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification
Published on: November 16, 2016
Characterization of a cryptic plasmid from an alpha-proteobacterial endosymbiont of Amoeba proteus
Miey Park1, Min-Soo Kim, Kyung-Min Lee
1Department of Biological Science, Seoul National University, Kwanak-Gu, Seoul 151-742, Republic of Korea.
Abstract:
A new cryptic plasmid pAP3.9 was discovered in symbiotic alpha-proteobacteria present in the cytoplasm of Amoeba proteus. The plasmid is 3869bp with a GC content of 34.66% and contains replication origins for both double-strand (dso) and single-strand (sso). It has three putative ORFs encoding Mob, Rep and phosphoglycolate phosphatase (PGPase). The pAP3.9 plasmid appears to propagate by the conjugative rolling-circle replication (RCR), since it contains all required factors such as Rep, sso and dso. Mob and Rep showed highest similarities to those of the cryptic plasmid pBMYdx in Bacillus mycoides. The PGPase was homologous to that of Bacillus cereus and formed a clade with those of Bacillus sp. in molecular phylogeny. These results imply that the pAP3.9 plasmid evolved by the passage through Bacillus species. We hypothesize that the plasmid-encoded PGPase may have contributed to the establishment of bacterial symbiosis within the hostile environment of amoeba cytoplasm.
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