1. Identification and characterization of toxin-antitoxin systems in strains of Lactobacillus rhamnosus isolated from humans.
- Author
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Klimina KM, Kjasova DK, Poluektova EU, Krügel H, Leuschner Y, Saluz HP, and Danilenko VN
- Subjects
- Adult, Amino Acid Sequence, Antitoxins isolation & purification, Bacterial Proteins chemistry, Bacterial Proteins isolation & purification, Base Sequence, Feces microbiology, Gene Expression Regulation, Bacterial, Humans, Infant, Infant, Newborn, Intestines microbiology, Polymorphism, Genetic, Russia, Saliva microbiology, Toxins, Biological isolation & purification, Antitoxins chemistry, Antitoxins genetics, Bacterial Proteins genetics, Lacticaseibacillus rhamnosus chemistry, Lacticaseibacillus rhamnosus genetics, Toxins, Biological chemistry, Toxins, Biological genetics
- Abstract
The toxin-antitoxin gene systems (TASs) are present in the genomes of the overwhelming majority of bacteria and archaea. These systems are involved in various cellular regulatory processes (including stress response), and have not been previously investigated in Lactobacilli. We identified 6 putative TASs with toxins belonging to the MazE and RelE superfamilies (PemK1-А1Lrh, PemK2-А2Lrh, PemK3-RelB2Lrh, RelE1Lrh, RelB3-RelE3Lrh, and YefM-YoeBLrh) in the genomes of annotated strains of Lactobacillus rhamnosus. PCR analyses revealed that all systems were found in the genomes of 15 strains of L. rhamnosus isolated from humans in central Russia. These strains were highly heterogeneous with respect to the presence of TASs, as well as their nucleotide and amino acid sequences. In three cases, the relE1 genes contained IS3 elements. TAS heterogeneity may be used to reveal inter-genus differences between strains. Cloning of the toxin genes of 3 TASs inhibited Escherichia coli growth, thus confirming their functionality. Cell growth arrest caused by expression of the toxin genes could be reverted by the expression of a cognate antitoxins. Transcription of toxin-antitoxin loci in L. rhamnosus was shown by RT-PCR., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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