title: Molecular cloning and characterization of caffeic acid 3-O-methyltransferase from the rhizome of Ligusticum chuanxiong.
abstract: OBJECTIVE
  To clone and characterize caffeic acid 3-O-methyltransferase (LcCOMT) from the rhizome of Ligusticum chuanxiong, a traditional medicinal herb having a high content of ferulic acid.
  
  
  RESULTS
  LcCOMT encoded an ORF of 362 amino acids with a calculated MW of 39,935 Da and pI of 5.94. Polygenetic tree indicated that LcCOMT was attributed to a new member of COMTs in plants. The recombinant LcCOMT was expressed in E. coli. HPLC and (1)H NMR analyses of purified LcCOMT protein confirmed that it could catalyze caffeic acid to produce ferulic acid in vitro. The further site-mutagenesis proved that His268 was one key catalytic residue. In addition, the substantial changing expression level of LcCOMT under chilling treatment suggested that LcCOMT might play important role in the accumulation of ferulic acid under chilling treatment.
  
  
  CONCLUSIONS
  This is the first report of the isolation and characterization of a COMT clone from traditional medicine containing high contents of pharmaceutical ferulic acid.
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China.
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Li
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China.
authors.forename: Gan
authors.initials: G
authors.lastname: Zhang
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China.
authors.forename: Ji-Hua
authors.initials: JH
authors.lastname: Yu
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China.
authors.forename: Yang-Yang
authors.initials: YY
authors.lastname: Li
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China.
authors.forename: Xin-He
authors.initials: XH
authors.lastname: Huang
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China.
authors.forename: Wan-Jun
authors.initials: WJ
authors.lastname: Wang
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Tan
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China. spinezhou@home.swjtu.edu.cn.
authors.forename: Jia-Yu
authors.initials: JY
authors.lastname: Zhou
authors.affiliation: College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, China. liaohai0918@163.com.
authors.forename: Hai
authors.initials: H
authors.lastname: Liao
mesh_terms: D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D030004:Ligusticum / Q000201:enzymology*; D008780:Methyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D027343:Rhizome / Q000201:enzymology*
chemical_list: D010940:Plant Proteins; D011994:Recombinant Proteins; D008780:Methyltransferases; C019608:caffeate O-methyltransferase
keywords: Caffeic acid 3-O-methyltransferase; Ferulic acid; Heterologous expression; Ligusticum chuanxiong; Molecular cloning