We report here the identification and characterization of mrdH, a novel chromosomal metal resistance determinant, located in the genomic island 55 of Pseudomonas putida KT2440. It encodes for MrdH, a predicted protein of ϳ40 kDa with a chimeric domain organization derived from the RcnA and RND (for resistance-nodulation-cell division) metal efflux proteins. The metal resistance function of mrdH was identified by the ability to confer nickel resistance upon its complementation into rcnA mutant (a nickel-and cobalt-sensitive mutant) of Escherichia coli. However, the disruption of mrdH in P. putida resulted in an increased sensitivity to cadmium and zinc apart from nickel. Expression studies using quantitative reverse transcription-PCR showed the induction of mrdH by cadmium, nickel, zinc, and cobalt. In association with mrdH, we also identified a conserved hypothetical gene mreA whose encoded protein showed significant homology to NreA and NreA-like proteins. Expression of the mreA gene in rcnA mutant of E. coli enhanced its cadmium and nickel resistance. Transcriptional studies showed that both mrdH and mreA underwent parallel changes in gene expression. The mobile genetic elements Tn4652 and IS1246, flanking mrdH and mreA were found to be induced by cadmium, nickel, and zinc, but not by cobalt. This study is the first report of a single-component metal efflux transporter, mrdH, showing chimeric domain organization, a broad substrate spectrum, and a location amid metal-inducible mobile genetic elements.Bacterial efflux systems for inorganic metal cations and anions play an imperative role in the regulatory network governing metal homeostasis. These efflux systems are also important for the environmental adaptability of the bacteria thriving in metal-rich serpentine environments. Bioinformatic and functional genomic analyses have revealed that the efflux systems belonging to the resistance-nodulation-cell division (RND), cation diffusion facilitator (CDF), and P-type ATPases constitute the majority of the multiple layers of heavy metal resistance in an organism (36). Members of the RND protein family include group of bacterial transport proteins involved in heavy metal resistance, nodulation, and cell division. The bestcharacterized RND family members include the efflux systems CzcCBA (Cd 2ϩ , Zn 2ϩ , and Co 2ϩ resistance), CnrCBA (Co 2ϩ

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Previous work from our laboratory involved the description of the Neurospora metal transportome, which included seven hypothetical zinc transporters belonging to the ZIP family. The aim of the present study was to make a comparative functional evaluation of two hypothetical zinc transporters named tzn1 (NCU07621.3) and tzn2 (NCU11414.3). Phenotypic analysis of tzn1 and tzn2 mutants and a double mutant (tzn1tzn2) revealed that the deletion of tzn1 causes aconidiation and a greater defect in growth than the single deletion of tzn2. Supplementation with zinc restores growth but not conidiation in tzn1 and tzn1tzn2. TZN1 complemented a zinc-uptake-deficient Saccharomyces cerevisiae mutant (zrt1zrt2) in zinc-deficient conditions, while tzn2 restored growth upon supplementation with zinc (0.05 mM). Furthermore, the Deltatzn1 mutant was found to have severely reduced zinc content indicating that tzn1 functions as a key regulator of intracellular zinc levels in Neurospora crassa. Zinc uptake studies indicate tzn1 is a specific transporter of zinc, while tzn2 transports both zinc and cadmium. Quantitative RT-PCR showed up-regulation of tzn1 (128-fold) under zinc-depleted conditions and down-regulation (>1,000-fold) in zinc-replete conditions. The present study indicates that the zinc transport proteins encoded by tzn1 and tzn2 are members of the zinc uptake system regulated by zinc status in N. crassa.

Plants are fantastic sources for present day life saving drugs. Monocrotaline a natural ligand exhibits dose-dependent cytotoxicity with potent antineoplastic activity. This study was intended to disclose the therapeutic potential of monocrotaline against hepatocellular carcinoma. The in silico predictions have highlighted the antineoplastic potential, druglikeness and biodegradability of monocrotaline. The in silico docking study has provided an insight and evidence for the antineoplastic activity of monocrotaline against p53, HGF and TREM1 proteins which play a threatening role in causing hepatocellular carcinoma. The mode of action of monocrotaline was determined experimentally by in vitro techniques such as XTT assay, NRU assay and whole cell brine shrimp assay have further supported our in silico studies. The in vitro cytotoxicity of monocrotaline was proved at IC50 24.966 µg/mL and genotoxicity at 2 X IC50 against HepG2 cells. Further, the credible druglike properties with non-mutagenicity, non-toxic on mammalian fibroblast and the potential antineoplastic activity through in vitro experimental validations established monocrotaline as a novel scaffold for liver cancer with superior efficacy and lesser side effects.

Background: The defensive capacities of plant protease Inhibitors (PI) rely on inhibition of proteases in insect guts or those secreted by microorganisms; and also prevent uncontrolled proteolysis and offer protection against proteolytic enzymes of pathogens.

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Objective: Staphylococcus aureus, a superbug and antibiotic resistant pathogen, is one of the most infection causing organism, ranging from skin allergies to severe lethal conditions. The prolonged use of different antibiotics and lack of optimal treatment over the antibiotic resistant species, led to the identification of new, better and promising therapeutic candidates.Methods: A systematic in silico filtration process was employed, which includes subtractive channels and reverse vaccinology techniques.Results: Here, we report 12 possible drug targets and two vaccine candidates based on essentiality, non-human homolog, virulent and localization, commonly in all the strains. Further characterization studies such as pathway analysis, chokepoint and structure prediction revealed, two proteins as the best drug targets one being novel and the other druggable. Only one protein has shown the characteristic feature of vaccine candidate, having antigenic property and an IgG binding domain. Conclusion:Two best drug targets were commonly identified in all the strains of S. aureus namely UDP-N-acetylmuramoyl-L-alanyl-D-glutamate--L-lysine ligase (MurE) and cell division protein FtsA, whereas the best common vaccine candidate includes Peptidoglycan binding protein. The therapeutic candidates reported in the present study might facilitate screening of new and better antimicrobial compounds, for an optimal treatment of S. aureus infections.

These results suggest ((2R)-2-[[1-[(2R)-2-(benzyloxycarbonylamino) propanoyl] piperidine-4-carbonyl]amino]-5-guanidino-pentan) as a promising lead molecule for developing a MurE inhibitor against treatment of S. aureus infections.