气候变化领域集成服务门户(CCPortal): A noncanonical vacuolar sugar transferase required for biosynthesis of antimicrobial defense compounds in oat

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DOI	10.1073/pnas.1914652116
	A noncanonical vacuolar sugar transferase required for biosynthesis of antimicrobial defense compounds in oat
	Orme A.; Louveau T.; Stephenson M.J.; Appelhagen I.; Melton R.; Cheema J.; Li Y.; Zhao Q.; Zhang L.; Fan D.; Tian Q.; Vickerstaff R.J.; Langdon T.; Han B.; Osbourn A.
发表日期	2019
ISSN	0027-8424
起始页码	27105
结束页码	27114
卷号	116 期号:52
英文摘要	Plants produce an array of natural products with important ecological functions. These compounds are often decorated with oligosaccharide groups that influence bioactivity, but the biosynthesis of such sugar chains is not well understood. Triterpene glycosides (saponins) are a large family of plant natural products that determine important agronomic traits, as exemplified by avenacins, antimicrobial defense compounds produced by oats. Avenacins have a branched trisaccharide moiety consisting of L-arabinose linked to 2 D-glucose molecules that is critical for antifungal activity. Plant natural product glycosylation is usually performed by uridine diphosphate-dependent glycosyltransferases (UGTs). We previously characterized the arabinosyltransferase that initiates the avenacin sugar chain; however, the enzymes that add the 2 remaining D-glucose molecules have remained elusive. Here we characterize the enzymes that catalyze these last 2 glucosylation steps. AsUGT91G16 is a classical cytosolic UGT that adds a 1,2-linked D-glucose molecule to L-arabinose. Unexpectedly, the enzyme that adds the final 1,4-linked D-glucose (AsTG1) is not a UGT, but rather a sugar transferase belonging to Glycosyl Hydrolase family 1 (GH1). Unlike classical UGTs, AsTG1 is vacuolar. Analysis of oat mutants reveals that AsTG1 corresponds to Sad3, a previously uncharacterized locus shown by mutation to be required for avenacin biosynthesis. AsTG1 and AsUGT91G16 form part of the avenacin biosynthetic gene cluster. Our demonstration that a vacuolar transglucosidase family member plays a critical role in triterpene biosynthesis highlights the importance of considering other classes of carbohydrate-active enzymes in addition to UGTs as candidates when elucidating pathways for the biosynthesis of glycosylated natural products in plants. © 2019 National Academy of Sciences. All rights reserved.
英文关键词	Biosynthetic gene clusters; Glycosylation; Natural products; Plant defense; Saponins
语种	英语
scopus关键词	1,2 linked dextro glucose; 1,4 linked dextro glucose; arabinose; avenacin; glucosidase; glycosidase; glycosyl hydrolase 1; saponin; transferase; triterpene; unclassified drug; uridine diphosphatedependent glycosyltransferase; antibiotic biosynthesis; Article; biocatalysis; controlled study; enzyme analysis; enzyme glycosylation; gene cluster; gene locus; gene mutation; mutagenesis; nonhuman; oat; phylogeny; priority journal; Sad3 gene; TG1 gene; transcriptomics
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160326
作者单位	Orme, A., Department of Metabolic Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom; Louveau, T., Department of Metabolic Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom; Stephenson, M.J., Department of Metabolic Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom; Appelhagen, I., Department of Metabolic Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom; Melton, R., Department of Metabolic Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom; Cheema, J., Department of Metabolic Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom; Li, Y., National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science, Centre of Excellence for Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China; Zhao, Q., National Centre for Gene Research, CAS-JIC Centre of Excellence for Plant and Microbial Science, Centre of...
推荐引用方式 GB/T 7714	Orme A.,Louveau T.,Stephenson M.J.,et al. A noncanonical vacuolar sugar transferase required for biosynthesis of antimicrobial defense compounds in oat[J],2019,116(52).
APA	Orme A..,Louveau T..,Stephenson M.J..,Appelhagen I..,Melton R..,...&Osbourn A..(2019).A noncanonical vacuolar sugar transferase required for biosynthesis of antimicrobial defense compounds in oat.Proceedings of the National Academy of Sciences of the United States of America,116(52).
MLA	Orme A.,et al."A noncanonical vacuolar sugar transferase required for biosynthesis of antimicrobial defense compounds in oat".Proceedings of the National Academy of Sciences of the United States of America 116.52(2019).