Phthalate, a plasticizer, endocrine disruptor, and potential carcinogen, is degraded by a variety of bacteria. This degradation is initiated by phthalate dioxygenase (PDO), a Rieske oxygenase (RO) that catalyzes the dihydroxylation of phthalate to a dihydrodiol. PDO has long served as a model for understanding ROs despite a lack of structural data. Here we purified PDO KF1 from Comamonas testosteroni KF1 and found that it had an apparent k cat / K m for phthalate of 0.58 ± 0.09 μM −1 s −1 , over 25-fold greater than for terephthalate. The crystal structure of the enzyme at 2.1 Å resolution revealed that it is a hexamer comprising two stacked α 3 trimers, a configuration not previously observed in RO crystal structures. We show that within each trimer, the protomers adopt a head-to-tail configuration typical of ROs. The stacking of the trimers is stabilized by two extended helices, which make the catalytic domain of PDO KF1 larger than that of other characterized ROs. Complexes of PDO KF1 with phthalate and terephthalate revealed that Arg207 and Arg244, two residues on one face of the active site, position these substrates for regiospecific hydroxylation. Consistent with their roles as determinants of substrate specificity, substitution of either residue with alanine yielded variants that did not detectably turnover phthalate. Together, these results provide critical insights into a pollutant-degrading enzyme that has served as a paradigm for ROs and facilitate the engineering of this enzyme for bioremediation and biocatalytic applications.

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Colon cancer is the most prevalent cause of death from cancer across the globe. Honey has the potentiality to control colon cancer.

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The rice root system is primarily composed of shoot-borne adventitious/crown roots (AR/CR) that develop from the coleoptile base, therefore is an excellent model system for studying shoot-to-root trans-differentiation process. We reveal global changes in protein and metabolite abundance, and protein phosphorylation in response to an auxin stimulus during CR development. The LC-MS/MS and GC-MS analyses of developing crown root primordia (CRP) and emerged CRs identified 334 proteins and 12 amino acids, respectively, that were differentially regulated upon auxin treatment. Gene ontology (GO) enrichment analysis of global proteome data uncovered the biological processes associated with chromatin conformational change, gene expression, and cell cycle that were regulated by auxin signaling. Spatial gene expression pattern analysis of differentially abundant proteins disclosed their stage-specific dynamic expression pattern during CRP development. Further, our tempo-spatial gene expression and functional analyses revealed that auxin creates a regulatory module during CRP development and activates ethylene biosynthesis exclusively during CRP initiation. Further, the phosphoproteome analysis identified 8,220 phosphosites, which could be mapped to 1,594 phosphoproteins and of which 66 phosphosites were differentially phosphorylated upon auxin treatment. Importantly, we observed differential phosphorylation of the Cyclin-dependent kinase G-2 (OsCDKG;2), and cell wall proteins, in response to auxin signaling, suggesting that auxin-dependent phosphorylation may be required for cell cycle activation, and cell wall synthesis during root organogenesis. Thus, our study provides evidence for the translational and post-translational regulation during CR development downstream of the auxin signaling pathway.

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Arthropod-borne viruses of the alphavirus and flavivirus genera are human pathogens of significant concern, and currently, no specific antiviral treatment is available for these viruses. In this study, the antiviral mechanisms of natural small molecules against Dengue virus (DENV) and Chikungunya virus (CHIKV) have been investigated. Herbacetin (HC) and Caffeic acid phenethyl ester (CAPE) showed depletion of polyamine levels in Vero cells as demonstrated by thin-layer chromatography (TLC). As polyamines are known to play a role in viral replication and transcription, HC and CAPE were expected to inhibit virus replication by reducing polyamine levels. To test this hypothesis, HC and CAPE were evaluated for antiviral activities using a cell-based virus yield assay by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), plaque reduction assay, and immunofluorescence assay (IFA). HC and CAPE displayed potent inhibition with EC50 of 463 nM and 0.417 nM for CHIKV and 8.5 uM and 1.15 uM for DENV, respectively. Interestingly, however, the addition of exogenous polyamines did not completely rescue the virus titer in both CHIKV and DENV infected cells and this indicated additional antiviral mechanisms for HC and CAPE. Further, in silico analysis indicated that HC and CAPE directly target the viral methyltransferases (MTase) of CHIKV and DENV. A high throughput ELISA-based assay that quantifies m7GMP-nsP1 adduct was employed to validate inhibition of CHIKV nsP1 MTase and IC50 was calculated to be 0.009 uM and 0.08 uM for CAPE and HC respectively. Altogether, the identification of natural small molecules as antivirals opens the door for the development of antiviral therapies for the treatment of CHIKV and DENV infections.

:The experiment has twenty four treatment combinations comprising of six main plots, organic manures mainly green leaf manure (GLM), enriched compost, FYM and vermicompost in combinations compared with RDF and FYM + RDF and four sub plots, liquid organic manures mainly bio-digester liquid manure, Panchagavya and cow-urine. The treatments comprised of application of 7.5 t FYM + RDF (100:50:25 N, P 2 O 5 , K 2 O kg ha -1 + 10 kg ZnSO 4 ) (RPP) and (100:50:25 N, P 2 O 5 , K 2 O kg ha -1 + 10 kg ZnSO 4 ) (RDF) alone exhibited significant effects on yield of sweet corn viz., with husk and without husk cob weight per plant, fresh cob yield, fresh and dry grain weight per plant and quality parameters viz., protein content, reducing and non-reducing sugar, total sugar, total soluble solids and total carbohydrates content in sweet corn kernels of sweet corn. Among the organic manurial combinations GLM + EC + VC (top dressing at GGS) recorded higher yield and quality of sweet corn with all liquid organic manures over basal applied vermicompost. Similarly, bio-digester and cow urine @ 10 per cent spray noticed higher yield and quality of sweet corn over control. Irrespective of organic manures, the dehydrogenase activity were significantly higher with GLM + FYM + VC (top dressing at GGS) and GLM + EC + VC (basal) equivalent to RDN over RPP and RDF.