Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.13.3 (histidine kinase)
 2,405 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A fundamental trade-off in biological systems is whether they consume resources to perform biological functions or save resources. Bacteria need to reliably and rapidly respond to input signals by using limited cellular resources. However, excessive resource consumption will become a burden for bacteria growth. To investigate the relationship between functional effectiveness and resource cost, we study the ubiquitous bifunctional enzyme circuit, which is robust to fluctuations in protein concentration and responds quickly to signal changes. We show that trade-off relationships exist between functional effectiveness and protein cost. Expressing more proteins of the circuit increases concentration robustness and response speed but affects bacterial growth. In particular, our study reveals a general relationship between free-energy dissipation rate, response speed, and concentration robustness. The dissipation of free energy plays an important role in the concentration robustness and response speed. High robustness can only be achieved with a large amount of free-energy consumption and protein cost. In addition, the noise of the output increases with increasing protein cost, while the noise of the response time decreases with increasing protein cost. We also calculate the trade-off relationships in the EnvZ-OmpR system and the nitrogen assimilation system, which both have the bifunctional enzyme. Similar results indicate that these relationships are mainly derived from the specific feature of the bifunctional enzyme circuits and are not relevant to the details of the models. According to the trade-off relationships, bacteria take a compromise solution that reliably performs biological functions at a reasonable cost.
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PMID:Trade-offs between effectiveness and cost in bifunctional enzyme circuit with concentration robustness. 3206 74

The CbrA/CbrB system is a two-component signal transduction system known to participate in the regulation of the cellular carbon/nitrogen balance and to play a central role in carbon catabolite repression in Pseudomonas species. CbrA is composed of a domain with similarity to proteins of the solute/sodium symporter family (SLC5) and domains typically found in bacterial sensor kinases. Here, the functional properties of the sensor kinase CbrA and its domains are analyzed at the molecular level using the system of the soil bacterium P. putida KT2440 as a model. It is demonstrated that CbrA can bind and transport L-histidine. Transport is specific for L-histidine and probably driven by an electrochemical proton gradient. The kinase domain is not required for L-histidine uptake by the SLC5 domain of CbrA, and has no significant impact on transport kinetics. Furthermore, it is shown that the histidine kinase can autophosphorylate and transfer the phosphoryl group to the response regulator CbrB. The SLC5 domain is not essential for these activities but appears to modulate the autokinase activity. A phosphatase activity of CbrA is not detected. None of the activities is significantly affected by L-histidine. The results demonstrate that CbrA functions as a L-histidine transporter and sensor kinase.
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PMID:Transport and kinase activities of CbrA of Pseudomonas putida KT2440. 3221 84

The Gram-negative bacterium Pseudomonas taiwanensis is a novel bacterium that uses shrimp shell waste as its sole sources of carbon and nitrogen. It is a versatile bacterium with potential for use in biological control, with activities including toxicity toward insects, fungi, and the rice pathogen Xanthomonas oryzae pv.oryzae (Xoo). In this study, the complete 5.08-Mb genome sequence of P. taiwanensis CMS was determined by a combination of NGS/Sanger sequencing and optical mapping. Comparison of optical maps of seven Pseudomonas species showed that P. taiwanensis is most closely related to P. putida KT 2400. We screened a total of 11,646 individual Tn5-transponson tagged strains to identify genes that are involved in the production and regulation of the iron-chelator pyoverdine in P. taiwanensis, which is a key anti-Xoo factor. Our results indicated that the two-component system (TCS) EnvZ/OmpR plays a positive regulatory role in the production of pyoverdine, whereas the sigma factor RpoS functions as a repressor. The knowledge of the molecular basis of the regulation of pyoverdine by P. taiwanensis provided herein will be useful for its development for use in biological control, including as an anti-Xoo agent.
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PMID:Whole Genome Sequencing and Tn5-Insertion Mutagenesis of Pseudomonas taiwanensis CMS to Probe Its Antagonistic Activity Against Rice Bacterial Blight Disease. 3320 95


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