title: Molecular cloning and biochemical characterization of a recombinant sterol 3-O-glucosyltransferase from Gymnema sylvestre R.Br. catalyzing biosynthesis of steryl glucosides.
abstract: Gymnema sylvestre R.Br., a pharmacologically important herb vernacularly called Gur-Mar (sugar eliminator), is widely known for its antidiabetic action. This property of the herb has been attributed to the presence of bioactive triterpene glycosides. Although some information regarding pharmacology and phytochemical profiles of the plant are available, no attempts have been made so far to decipher the biosynthetic pathway and key enzymes involved in biosynthesis of steryl glucosides. The present report deals with the identification and catalytic characterization of a glucosyltransferase, catalyzing biosynthesis of steryl glycosides. The full length cDNA (2572 bp) contained an open reading frame of 2106 nucleotides that encoded a 701 amino acid protein, falling into GT-B subfamily of glycosyltransferases. The GsSGT was expressed in Escherichia coli and biochemical characterization of the recombinant enzyme suggested its key role in the biosynthesis of steryl glucosides with catalytic preference for C-3 hydroxyl group of sterols. To our knowledge, this pertains to be the first report on cloning and biochemical characterization of a sterol metabolism gene from G. sylvestre R.Br. catalyzing glucosylation of a variety of sterols of biological origin from diverse organisms such as bacteria, fungi, and plants.
authors.affiliation: Metabolic and Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Lucknow, Uttar Pradesh 226015, India.
authors.forename: Pragya
authors.identifier: 0000-0001-7602-2562
authors.initials: P
authors.lastname: Tiwari
authors.affiliation: Metabolic and Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Lucknow, Uttar Pradesh 226015, India ; Centre of Innovative and Applied Bioprocessing, (A National Institute under Department of Biotechnology Gov. of India) C-127, Phase-8, Industrial Area, S.A.S. Nagar, Mohali, Punjab 160071, India.
authors.forename: Rajender Singh
authors.initials: RS
authors.lastname: Sangwan
authors.affiliation: Metabolic and Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Lucknow, Uttar Pradesh 226015, India.
authors.lastname: Asha
authors.affiliation: Department of Biotechnology, Uttar Pradesh Technical University, Lucknow, Uttar Pradesh 226021, India.
authors.forename: B N
authors.initials: BN
authors.lastname: Mishra
authors.affiliation: Metabolic and Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Lucknow, Uttar Pradesh 226015, India.
authors.forename: Farzana
authors.identifier: 0000-0002-0181-989X
authors.initials: F
authors.lastname: Sabir
authors.affiliation: Metabolic and Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Lucknow, Uttar Pradesh 226015, India.
authors.forename: Neelam S
authors.initials: NS
authors.lastname: Sangwan
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D003001:Cloning, Molecular / Q000379:methods; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000502:physiology*; D005960:Glucosides / Q000737:chemistry*; D005964:Glucosyltransferases / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D031104:Gymnema sylvestre / Q000502:physiology*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D005960:Glucosides; D011994:Recombinant Proteins; D005964:Glucosyltransferases; C085360:sterol 3-beta-glucosyltransferase