Project description:Nucleoid-associated proteins (NAPs) are known to fold bacterial DNA and influence global transcription. Incompatibility P-7 plasmid pCAR1 carries three genes encoding NAPs: H-NS family protein Pmr, NdpA-like protein Pnd, and HU-like protein Phu. Because previous reports about plasmid-encoded NAPs mainly focused on H-NS homologs, functions and importance of different kinds of NAPs encoded on a plasmid remained unknown. Here, we assessed the effects of single or double disruption of pmr, pnd, and phu in a host P. putida KT2440. When pmr and pnd or pmr and phu were disrupted simultaneously, stability and conjugation frequency of pCAR1 decreased significantly. In the comprehensive phenotypes comparisons, host availabilities of some compounds, which were reduced by pCAR1carriage, were restored by NAP-gene(s)-disruption. Transcriptome analyses showed that Pmr and Pnd have different regulons, whereas Phu mainly supports their gene regulation. These cooperative functions of the three NAPs were not simply due to protein-protein interactions because hetero-oligomers of them were not detected in pull-down assays. Our present study is the first report about the cooperative function of plasmid-encoded different kinds of NAPs, which show no homology with each other.
Project description:Nucleoid-associated proteins (NAPs) are known to fold bacterial DNA and influence global transcription. Incompatibility P-7 plasmid pCAR1 carries three genes encoding NAPs: H-NS family protein Pmr, NdpA-like protein Pnd, and HU-like protein Phu. Because previous reports about plasmid-encoded NAPs mainly focused on H-NS homologs, functions and importance of different kinds of NAPs encoded on a plasmid remained unknown. Here, we assessed the effects of single or double disruption of pmr, pnd, and phu in a host P. putida KT2440. When pmr and pnd or pmr and phu were disrupted simultaneously, stability and conjugation frequency of pCAR1 decreased significantly. In the comprehensive phenotypes comparisons, host availabilities of some compounds, which were reduced by pCAR1carriage, were restored by NAP-gene(s)-disruption. Transcriptome analyses showed that Pmr and Pnd have different regulons, whereas Phu mainly supports their gene regulation. These cooperative functions of the three NAPs were not simply due to protein-protein interactions because hetero-oligomers of them were not detected in pull-down assays. Our present study is the first report about the cooperative function of plasmid-encoded different kinds of NAPs, which show no homology with each other. The NAPs-dependent change of RNA maps in early exponential phases.
Project description:Nucleoid-associated proteins (NAPs) are known to fold bacterial DNA and influence global transcription. Incompatibility P-7 plasmid pCAR1 carries three genes encoding NAPs: H-NS family protein Pmr, NdpA-like protein Pnd, and HU-like protein Phu. Because previous reports about plasmid-encoded NAPs mainly focused on H-NS homologs, functions and importance of different kinds of NAPs encoded on a plasmid remained unknown. Here, we assessed the effects of single or double disruption of pmr, pnd, and phu in a host P. putida KT2440. When pmr and pnd or pmr and phu were disrupted simultaneously, stability and conjugation frequency of pCAR1 decreased significantly. In the comprehensive phenotypes comparisons, host availabilities of some compounds, which were reduced by pCAR1carriage, were restored by NAP-gene(s)-disruption. Transcriptome analyses showed that Pmr and Pnd have different regulons, whereas Phu mainly supports their gene regulation. These cooperative functions of the three NAPs were not simply due to protein-protein interactions because hetero-oligomers of them were not detected in pull-down assays. Our present study is the first report about the cooperative function of plasmid-encoded different kinds of NAPs, which show no homology with each other.
Project description:Nucleoid-associated proteins (NAPs) are known to fold bacterial DNA and influence global transcription. Incompatibility P-7 plasmid pCAR1 carries three genes encoding NAPs: H-NS family protein Pmr, NdpA-like protein Pnd, and HU-like protein Phu. Because previous reports about plasmid-encoded NAPs mainly focused on H-NS homologs, functions and importance of different kinds of NAPs encoded on a plasmid remained unknown. Here, we assessed the effects of single or double disruption of pmr, pnd, and phu in a host P. putida KT2440. When pmr and pnd or pmr and phu were disrupted simultaneously, stability and conjugation frequency of pCAR1 decreased significantly. In the comprehensive phenotypes comparisons, host availabilities of some compounds, which were reduced by pCAR1carriage, were restored by NAP-gene(s)-disruption. Transcriptome analyses showed that Pmr and Pnd have different regulons, whereas Phu mainly supports their gene regulation. These cooperative functions of the three NAPs were not simply due to protein-protein interactions because hetero-oligomers of them were not detected in pull-down assays. Our present study is the first report about the cooperative function of plasmid-encoded different kinds of NAPs, which show no homology with each other. The NAPs-dependent change of chromosomal RNA maps in early exponential phases.
Project description:Nucleoid-associated proteins (NAPs), which fold bacterial DNA and influence gene transcription, are considered to be global transcriptional regulators of genes on both plasmids and the host chromosome. Incompatibility P-7 group plasmid pCAR1 carries genes encoding three NAPs: H-NS family protein Pmr, NdpA-like protein Pnd, and HU-like protein Phu. In this study, the effects of single or double disruption of pmr, pnd, and phu were assessed in host Pseudomonas putida KT2440. When pmr and pnd or pmr and phu were simultaneously disrupted, both the segregational stability and the structural stability of pCAR1 were markedly decreased, suggesting that Pmr, Pnd, and Phu act as plasmid-stabilizing factors in addition to their established roles in replication and partition systems. The transfer frequency of pCAR1 was significantly decreased in these double mutants. The segregational and structural instability of pCAR1 in the double mutants was recovered by complementation of pmr, whereas no recovery of transfer deficiency was observed. Comprehensive phenotype comparisons showed that the host metabolism of carbon compounds, which was reduced by pCAR1 carriage, was restored by disruption of the NAP gene(s). Transcriptome analyses of mutants indicated that transcription of genes for energy production, conversion, inorganic ion transport, and metabolism were commonly affected; however, how their products altered the phenotypes of mutants was not clear. The findings of this study indicated that Pmr, Pnd, and Phu act synergistically to affect pCAR1 replication, maintenance, and transfer, as well as to alter the host metabolic phenotype.
Project description:MvaT proteins are members of the H-NS family of proteins in pseudomonads. The IncP-7 conjugative plasmid pCAR1 carries an mvaT-homologous gene, pmr. In Pseudomonas putida KT2440 bearing pCAR1, pmr and the chromosomally carried homologous genes, turA and turB, are transcribed at high levels, and Pmr interacts with TurA and TurB in vitro. In the present study, we clarified how the three MvaT proteins regulate the transcriptome of P. putida KT2440(pCAR1). Analyses performed by a modified chromatin immunoprecipitation assay with microarray technology (ChIP-chip) suggested that the binding regions of Pmr, TurA, and TurB in the P. putida KT2440(pCAR1) genome are almost identical; nevertheless, transcriptomic analyses using mutants with deletions of the genes encoding the MvaT proteins during the log and early stationary growth phases clearly suggested that their regulons were different. Indeed, significant regulon dissimilarity was found between Pmr and the other two proteins. Transcription of a larger number of genes was affected by Pmr deletion during early stationary phase than during log phase, suggesting that Pmr ameliorates the effects of pCAR1 on host fitness more effectively during the early stationary phase. Alternatively, the similarity of the TurA and TurB regulons implied that they might play complementary roles as global transcriptional regulators in response to plasmid carriage.
Project description:MvaT proteins are recognized as a member of H-NS family proteins in pseudomonads. IncP-7 conjugative plasmid pCAR1, which was originally found in Pseudomonas resinovorans, carries an mvaT homologous gene, pmr. In Pseudomonas putida KT2440 bearing pCAR1, it was previously reported that pmr and chromosomally-encoded homologous genes, turA and turB, are majorly transcribed, and that Pmr interacts with TurA and TurB in vitro (Yun et al. J. Bacteriol. 192:4720-4731, 2010). In the present study, we clarified how the three MvaT proteins regulate the transcriptome of P. putida KT2440(pCAR1). Modified ChIP-chip analyses suggested that the binding sites of Pmr, TurA, and TurB in P. putida KT2440(pCAR1) genome were almost identical; nevertheless, transcriptome analyses using deletion mutants of each MvaT protein gene at the log and early-stationary growth phases clearly suggested that their regulons were different with one another. Especially, significant dissimilarity of regulons was found between Pmr and other two proteins. Transcriptions of the larger number of genes were affected by Pmr deletion at the early-stationary phase than at the log phase, suggesting that Pmr minimizes the pCAR1 effects on host fitness more effectively at the early-stationary phase. On the other hand, similarity found between the regulons of TurA and TurB implied that they may have complementary roles as global transcriptional regulators in response to the plasmid carriage.
Project description:MvaT proteins are recognized as a member of H-NS family proteins in pseudomonads. IncP-7 conjugative plasmid pCAR1, which was originally found in Pseudomonas resinovorans, carries an mvaT homologous gene, pmr. In Pseudomonas putida KT2440 bearing pCAR1, it was previously reported that pmr and chromosomally-encoded homologous genes, turA and turB, are majorly transcribed, and that Pmr interacts with TurA and TurB in vitro (Yun et al. J. Bacteriol. 192:4720-4731, 2010). In the present study, we clarified how the three MvaT proteins regulate the transcriptome of P. putida KT2440(pCAR1). Modified ChIP-chip analyses suggested that the binding sites of Pmr, TurA, and TurB in P. putida KT2440(pCAR1) genome were almost identical; nevertheless, transcriptome analyses using deletion mutants of each MvaT protein gene at the log and early-stationary growth phases clearly suggested that their regulons were different with one another. Especially, significant dissimilarity of regulons was found between Pmr and other two proteins. Transcriptions of the larger number of genes were affected by Pmr deletion at the early-stationary phase than at the log phase, suggesting that Pmr minimizes the pCAR1 effects on host fitness more effectively at the early-stationary phase. On the other hand, similarity found between the regulons of TurA and TurB implied that they may have complementary roles as global transcriptional regulators in response to the plasmid carriage. ChIP-chip: Pseudomonas putida KT2440 harboring plasmid pCAR1 cells were ChIPed with His-tag (C-terminus of each MvaT homologs) and compared with input control. Transcriptome analysis: pCAR1 RNA maps of mvaT deletion mutants were compared with those of wild-type cells.
Project description:Self-transmissible plasmids are classified into two types based on their sex pili: short and rigid pili, and long and flexible pili. The transferability of two plasmids with different types of sex pili, pBP136 and pCAR1, was compared in stirring liquid conditions with different cell density. The most probable number method to count transconjugants could detect differences in the transfer frequency with higher resolution in comparison with the conventional CFU counting method. Both plasmids showed higher transfer frequency in high stirring rates than static liquid conditions when the donor and recipient density was 106-107 CFU mL-1. The probability of donor-initiated plasmid transfer was investigated by a single-cell-level analysis using a cell sorter. The probability was >36-fold higher for pBP136 than for pCAR1; thus, the simulated transfer frequency of pBP136 was much higher than that of pCAR1 in stirring liquid conditions. Nevertheless, the transfer frequency of pCAR1 was as high as that of pBP136 when the donor and recipient cell density was 106 CFU mL-1. This fact indicates that the lower probability of the donor pCAR1 to initiate transfer could be overcome by its high tolerance to the shearing force between donor and recipient cells under higher stirring liquid conditions. Our findings can explain the different survival strategies of these two types of plasmids based on their preferences of transfer conditions.