title: Molecular and biochemical characterization of squalene synthase from Siraitia grosvenorii.
abstract: OBJECTIVE
  To clone and characterize the squalene synthase from Siraitia grosvenorii (SgSQS).
  
  
  RESULTS
  The gene encoding SgSQS was cloned. SgSQS has 417 amino acid residues with an pI of 7.3. There are 32 phosphorylation sites in its sequence: S48as well as S196play important roles in regulation of enzyme activity. The enzyme is a monomeric protein with a cave-like active center formed by α helixes and has two transmembrane domains at its C-terminus. SgSQS mRNA expression in stem and root were about twice as much as that in leaf and peel. Full-length SgSQS with measurable catalytic activity was expressed in Escherichia coli. SgSQS activity was optimal at 37 °C and pH 7.5 respectively.
  
  
  CONCLUSIONS
  SgSQS gene was cloned, and the molecular structure and biochemical function of SgSQS were characterized.
authors.affiliation: Department of Biochemistry and Molecular Biology, Guangxi Medical University, Nanning, Guangxi, 530000, China.
authors.forename: Heling
authors.initials: H
authors.lastname: Su
authors.affiliation: Key Laboratory of Medicinal Biotechnology, Guilin Medical University, Guilin, Guangxi, 541004, China.
authors.forename: Yongming
authors.identifier: http://orcid.org/0000-0002-6116-7205
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Medicinal Biotechnology, Guilin Medical University, Guilin, Guangxi, 541004, China.
authors.forename: Yalun
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Medicinal Biotechnology, Guilin Medical University, Guilin, Guangxi, 541004, China.
authors.forename: Yanlian
authors.initials: Y
authors.lastname: Tan
authors.affiliation: Key Laboratory of Medicinal Biotechnology, Guilin Medical University, Guilin, Guangxi, 541004, China.
authors.forename: Yunyan
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Key Laboratory of Medicinal Biotechnology, Guilin Medical University, Guilin, Guangxi, 541004, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liang
authors.affiliation: Key Laboratory of Medicinal Biotechnology, Guilin Medical University, Guilin, Guangxi, 541004, China.
authors.forename: Hongli
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Biochemistry and Molecular Biology, Guangxi Medical University, Nanning, Guangxi, 530000, China. wuyaosheng03@sina.com.
authors.forename: Yaosheng
authors.initials: Y
authors.lastname: Wu
mesh_terms: D020134:Catalytic Domain; D003001:Cloning, Molecular; D019662:Cucurbitaceae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D020869:Gene Expression Profiling; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D010766:Phosphorylation; D018515:Plant Leaves / Q000201:enzymology; D018517:Plant Roots / Q000201:enzymology; D018547:Plant Stems / Q000201:enzymology; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000032:analysis; D013696:Temperature
chemical_list: D012333:RNA, Messenger; D013186:Farnesyl-Diphosphate Farnesyltransferase
keywords: Cloning; Enzymatic properties; Gene expression; Sequence analysis; Siraitia grosvenorii; Squalene synthase