title: De novo biosynthesis of pterostilbene in an Escherichia coli strain using a new resveratrol O-methyltransferase from Arabidopsis.
abstract: BACKGROUND
  Pterostilbene, a structural analog of resveratrol, has higher oral bioavailability and bioactivity than that of the parent compound; but is far less abundant in natural sources. Thus, to efficiently obtain this bioactive resveratrol analog, it is necessary to develop new bioproduction systems.
  
  
  RESULTS
  We identified a resveratrol O-methyltransferase (ROMT) function from a multifunctional caffeic acid O-methyltransferase (COMT) originating from Arabidopsis, which catalyzes the transfer of a methyl group to resveratrol resulting in pterostilbene production. In addition, we constructed a biological platform to produce pterostilbene with this ROMT gene. Pterostilbene can be synthesized from intracellular L-tyrosine, which requires the activities of four enzymes: tyrosine ammonia lyase (TAL), p-coumarate:CoA ligase (CCL), stilbene synthase (STS) and resveratrol O-methyltransferase (ROMT). For the efficient production of pterostilbene in E. coli, we used an engineered E. coli strain to increase the intracellular pool of L-tyrosine, which is the initial precursor of pterostilbene. Next, we tried to produce pterostilbene in the engineered E. coli strain using L-methionine containing media, which is used to increase the intracellular pool of S-adenosyl-L-methionine (SAM). According to this result, pterostilbene production as high as 33.6 ± 4.1 mg/L was achieved, which was about 3.6-fold higher compared with that in the parental E. coli strain harboring a plasmid for pterostilbene biosynthesis.
  
  
  CONCLUSIONS
  As a potential phytonutrient, pterostilbene was successfully produced in E. coli from a glucose medium using a single vector system, and its production titer was also significantly increased using a L-methionine containing medium in combination with a strain that had an engineered metabolic pathway for L-tyrosine. Additionally, we provide insights into the dual functions of COMT from A. thaliana which was characterized as a ROMT enzyme.
authors.affiliation: Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji-ro, Ochang-eup, Chungbuk, 363-883, Republic of Korea.|Major of Biomolecular Science, University of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Kyung Taek
authors.initials: KT
authors.lastname: Heo
authors.affiliation: Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji-ro, Ochang-eup, Chungbuk, 363-883, Republic of Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Kang
authors.affiliation: Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji-ro, Ochang-eup, Chungbuk, 363-883, Republic of Korea. hongsoo@kribb.re.kr.|Major of Biomolecular Science, University of Science and Technology, Daejeon, Republic of Korea. hongsoo@kribb.re.kr.
authors.forename: Young-Soo
authors.identifier: http://orcid.org/0000-0001-7768-2239
authors.initials: YS
authors.lastname: Hong
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D000642:Ammonia-Lyases / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology*; D055162:Biocatalysis; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways; D008715:Methionine / Q000494:pharmacology; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism*; D000077185:Resveratrol; D012436:S-Adenosylmethionine / Q000378:metabolism; D013267:Stilbenes / Q000737:chemistry / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D013267:Stilbenes; C107773:pterostilbene; D014443:Tyrosine; D012436:S-Adenosylmethionine; D008715:Methionine; D008780:Methyltransferases; C019608:caffeate O-methyltransferase; D000217:Acyltransferases; C022674:stilbene synthase; D000642:Ammonia-Lyases; C023208:L-tyrosine ammonia-lyase; D000077185:Resveratrol
keywords: De novo biosynthesis; Pterostilbene; Resveratrol O-methyltransferase