02370nas a2200265   4500008004100000022001400041245011700055210006900172260000800241300001400249490000800263520148700271653002501758653002401783653002401807653001401831653002101845100001701866700002001883700001601903700001601919700002401935700001801959856012701977       2019                        eng d  a1742-464X00aMechanistic insights into enzymatic catalysis by trehalase from the insect gut endosymbiont Enterobacter cloacae0 aMechanistic insights into enzymatic catalysis by trehalase from   cMAY  a1700-17160 v2863 a<p>Energy metabolism in the diamondback moth Plutella xylostella is facilitated by trehalase, an enzyme which assists in trehalose hydrolysis, from the predominant gut bacterium Enterobacter cloacae. We report the biochemical and structural characterization of recombinant trehalase from E. cloacae (Px_EclTre). Px_EclTre showed K-M of 1.47 (+/- 0.05) mm, k(cat) of 6254.72 min(-1) and V-max 0.2 (+/- 0.002) mm center dot min(-1) at 55 degrees C and acidic pH. Crystal structures of Px_EclTre were determined in the ligand-free form and bound to the inhibitor Validoxylamine A. The crystal structure of the ligand-free form, unavailable until now for any other bacterial trehalases, enabled us to delineate the conformational changes accompanying ligand binding in trehalases. Multiple salt bridges were identified that potentially facilitated closure of a hood over the substrate-binding site. A cluster of five tryptophans lined the -1 substrate-binding subsite, interacted with crucial active site residues and contributed to both trehalase activity and stability. The importance of these residues in enzyme activity was further validated by mutagenesis studies. Many of these identified residues form part of signature motifs and other conserved sequences in trehalases. The structure analysis thus led to the assignment of the functional role to these conserved residues. This information can be further explored for the design of effective inhibitors against trehalases.</p>
10aEnterobacter cloacae10aPlutella xylostella10astructural analysis10atrehalase10avalidoxylamine A1 aAdhav, Anmol1 aHarne, Shrikant1 aBhide, Amey1 aGiri, Ashok1 aGayathri, Pananghat1 aJoshi, Rakesh  uhttps://library.ncl.res.in/content/mechanistic-insights-enzymatic-catalysis-trehalase-insect-gut-endosymbiont-enterobacter02816nas a2200265   4500008004100000022001400041245008900055210006900144260000800213300001100221490000700232520198500239653002002224653001202244653002002256653001502276653002402291653001302315653001802328100002302346700002502369700002002394700002402414856011202438       2025                        eng d  a1744-117X00aHigh levels of sinigrin trigger synthesis of fatty acids in Plutella xylostella (L.)0 aHigh levels of sinigrin trigger synthesis of fatty acids in Plut  cJUN  a1014240 v543 a<p>
	Diamondback moth (Lepidoptera: Plutellidae; Plutella xylostella L.) is a specialist insect of the Brassicaceae family, damaging economically important crops, such as cabbage and cauliflower. Glucosinolates, also known as `mustard oil bombs' are present in all Brassicaceae members, of which sinigrin (allyl-glucosinolate or 2-propenylglucosinolate) is a major aliphatic compound. During herbivory, glucosinolates are converted to toxic isothiocyanates that deter insect pests. P. xylostella possesses glucosinolate sulfatases that desulfate them. Such a conversion renders them unfit for degradation to toxic products. Changes in the larval performance prompted us for RNA sequencing to understand probable adaptation mechanism under sinigrin stress. Differentially expressed genes were found to be related to larval cuticle proteins. Further, gene ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses depict genes belonging to the categories, integral component of membrane, cellular processes and those involved in biosynthesis of fatty acids. Upregulation of cuticular genes viz. larval cuticle protein-17 (LCP-17), cuticular protein-19 (2CP-19) and ATP binding cassette transporter C7 (ABCC7), ABCC16 was validated by qRT-PCR. Liquid chromatography quadrupole time of flight mass spectrometry analysis of whole larvae feeding on sinigrin and their separated cuticle, depicted abundance of fatty acids. Changes in the topography of the larval cuticle were evident by scanning electron microscopy. Expression of PxABCH1 was corroborated to its role in the transport of cuticular lipids. Notably, molecular docking of PxABCH1 with cuticular fatty acids showed favorable binding interactions. To summarize, integrated transcriptomic and metabolomic analyses suggest that in response to a diet containing a high dose of sinigrin, P. xylostella re-programs metabolic pathways related to fatty acid biosynthesis that directly influence insect development.</p>
10aABC transporter10aCuticle10aHost metabolite10aMetabolome10aPlutella xylostella10aSinigrin10aTranscriptome1 aBarve, Pranoti, R.1 aBarvkar, Vitthal, T.1 aGiri, Ashok, P.1 aKotkar, Hemlata, M.  uhttps://library.ncl.res.in/content/high-levels-sinigrin-trigger-synthesis-fatty-acids-plutella-xylostella-l