Project description:Bacillus velezensis strain GH1-13 with a native conjugative plasmid (pBV71) is thought to be beneficial to the bacterium, although no information on its effects exists. Here we show that strain GH1-13 frequently lost the plasmid during normal growth conditions in a rich medium and changed the morphology and sensitivity to selenite and tellurite. Compared to the plasmid-cured cells, the wild-type and complemented cells exhibited multicellular behavior with the expression of conjugative type IV pili and regulatory Rap homologous genes that regulate the interconnection between conjugation and biofilm formation. Further omics-based analyses of morphogenesis, biofilm formation, and antibiotic synthesis suggest that the conjugative plasmid activates envelope stress responses in association with increased biosynthesis of extracellular polysaccharide and antibiotics for protective functions of the host during exponential phase.
Project description:Integrative and conjugative elements (ICEs), a.k.a., conjugative transposons, are mobile genetic elements involved in many biological processes, including the spread of antibiotic resistance. Unlike conjugative plasmids that are extra-chromosomal and replicate autonomously, ICEs are integrated in the chromosome and replicate passively during chromosomal replication. It is generally thought that ICEs do not replicate autonomously. We found that when induced, Bacillus subtilis ICEBs1 replicates as a plasmid. The ICEBs1 origin of transfer (oriT) served as the origin of replication and the conjugal DNA relaxase served as the replication initiation protein. Autonomous replication of ICEBs1 conferred genetic stability to the excised element, but was not required for mating. The B. subtilis helicase PcrA that mediates unwinding and replication of Gram-positive rolling circle replicating plasmids was required for ICEBs1 replication and mating. Nicking of oriT by the relaxase and unwinding by PcrA likely directs transfer of a single-strand of ICEBs1 into recipient cells. This SuperSeries is composed of the SubSeries listed below.
Project description:We analyzed gene expression during conjugative transfer of plasmid RP4. Pairs of rifampicin-susceptible (RifS) and -resistance (RifR) strains of Pseudomonas putida KT2440 were conjugated for 10 minute on filter membrane in the presence of rifampicin to discriminate the expression changes in the donor and recipient cells.
Project description:we examined the three different mature biofilms and searched the genes which promoted the rapid biofilm formation when their population hosing the plasmids. We investigate the global transcriptional differences between the non-conjugative or conjugative plasmid-carrying and plasmid-free strains.
Project description:Lactobacillus sakei MBEL1397(=KCTC14037BP) was isolated from kimchi, a traditional Korean fermented food, in Gangwon province, Republic of Korea. MBEL1397 is an acid-tolerant strain with antimicrobial activity and α-glucosidase inhibitory activity, which might be preliminary indications of its probiotic properties. Complete genome sequencing of L. sakei MBEL1397 was performed using the PacBio RSII platform. MBEL1397 has a 1,994,569 bp circular chromosome with 41.04% G+C content. The genome includes 1,946 protein-coding genes, 66 transfer RNA genes, and 21 ribosomal RNA genes. The BioProject has been deposited at DDBJ/EMBL/GenBank. The GenBank accession numbers are PRJNA598112 for the BioProject, SAMN13698554 for the BioSample, and CP048116 for the chromosome.
Project description:The type VI secretion system (T6SS) is a highly sophisticated nanomachine widely used by bacteria to achieve competitive advantage and to potentiate horizontal gene transfer. Plasmid conjugation plays crucial roles in bacterial evolution by driving adaptation to environmental stimuli and pathogenicity. The lethal effect mediated by T6SS is detrimental to horizontal gene transfer by conjugation, while bacteria have evolved T6SS repression mechanisms regulated by plasmid to accomplish conjugative transfer. Two TetR family regulators encoded by large conjugative plasmid (LCP) in Acinetobacter baumannii have been proved similar in T6SS restriction, which seems redundant in function. Here, the global regulation roles and multiple DNA binding sites of two plasmid-sourced TetRs were identified. The two TetRs showed distinct preferences in similar roles of T6SS inhibition and binding with DNA probes. Crystal structures of TetRs were solved for illuminating the regulatory mechanism and possible reasons for difference in functions. In addition, plasmid-sourced TetRs also significantly downregulated biofilm formation and bacterial colonization, as well as influenced bacterial virulence in cultured cells and murine pneumonia infection models. Taken together, this work comprehensively elucidates the roles and regulatory mechanisms of TetRs and clarifies their similarity and difference in function, providing insights into plasmid encoded chromosome regulation pathways.
Project description:The type VI secretion system (T6SS) is a highly sophisticated nanomachine widely used by bacteria to achieve competitive advantage and to potentiate horizontal gene transfer. Plasmid conjugation plays crucial roles in bacterial evolution by driving adaptation to environmental stimuli and pathogenicity. The lethal effect mediated by T6SS is detrimental to horizontal gene transfer by conjugation, while bacteria have evolved T6SS repression mechanisms regulated by plasmid to accomplish conjugative transfer. Two TetR family regulators encoded by large conjugative plasmid (LCP) in Acinetobacter baumannii have been proved similar in T6SS restriction, which seems redundant in function. Here, the global regulation roles and multiple DNA binding sites of two plasmid-sourced TetRs were identified. The two TetRs showed distinct preferences in similar roles of T6SS inhibition and binding with DNA probes. Crystal structures of TetRs were solved for illuminating the regulatory mechanism and possible reasons for difference in functions. In addition, plasmid-sourced TetRs also significantly downregulated biofilm formation and bacterial colonization, as well as influenced bacterial virulence in cultured cells and murine pneumonia infection models. Taken together, this work comprehensively elucidates the roles and regulatory mechanisms of TetRs and clarifies their similarity and difference in function, providing insights into plasmid encoded chromosome regulation pathways.
Project description:Complete nucleotide sequence and determination of the replication region of the sporulation inhibiting plasmid p576 from Bacillus pumilus NRS576.
Project description:Impacts of plasmid carriage on its host cell were comprehensively analyzed using conjugative plasmid pCAR1 in the three different kinds of hosts, Pseudomonas putida KT2440, P. aeruginosa PAO1, and P. fluorescens Pf0-1. Various analyses of the host phenotype showed that pCAR1 carriage reduced host fitness, swimming motility, and resistances to osmotic- or pH-stress, and brought about the alterations of primary metabolic capacities in the TCA cycle or those several steps away from the TCA cycle in the host cells. Growth phase-dependent transcriptome analyses were performed with the classification of the annotated genes based on their identities among the three hosts and their putative functions. pCAR1 carriage affected host transcriptome more greatly at the transition and stationary phases in each host. The transcriptome responses were more similar between KT2440 and PAO1 than between other host combinations, and many genes, such as for ribosomal proteins, F-type ATPase, and RNAP core, in both strains were commonly not suppressed in their stationary phases. These responses may have resulted in the reduction of host fitness, motility, and stress resistances. Host-specific responses to plasmid carriage were transcriptional changes of genes on putative prophage or foreign DNA regions. The extent of the impacts in host phenotypes and transcriptomes was similarly the largest in KT2440 and the lowest in Pf0-1. The host alterations controlled by pCAR1 carriage are important for understanding the fate of the plasmid and its host, plasmid maintenance, expression of plasmid genes, the host cell physiology, and host survivability in the environment.