title: Cloning and expression of pathogenesis-related protein 4 from jelly fig (Ficus awkeotsang Makino) achenes associated with ribonuclease, chitinase and anti-fungal activities.
abstract: A cDNA fragment (FaPR4) encoding a class I pathogenesis-related protein 4 (PR-4) from Ficus awkeotsang was obtained by PCR cloning. Plant PR-4s were grouped into class I and II, differing by the presence of ChtBD and hinge. The predicted mature FaPR4 comprises N-terminal chitin-binding domain (ChtBD), hinge, Barwin domain and C-terminal extension. FaPR4-C, an N-terminal truncated form of FaPR4, was designed to mimic the structural feature of class II PR-4s. FaPR4 and FaPR4-C were over-expressed in yeast Pichia pastoris, and both recombinants exhibited RNase and anti-fungal activities. To our knowledge, it is the first report that FaPR4, a member of class I PR-4s has RNase activity as class II. FaPR4 possesses better anti-fungal activities toward Fusarium oxysporum and Sclerotium rolfsii than FaPR4-C. Heat-treated FaPR4 remained RNase and anti-fungal activities; while heat-treated FaPR4-C lost those activities. Therefore, ChtBD of FaPR4 may not only contribute to its anti-fungal but also improve the thermal stability of protein. It also implied the correlation of RNase activity with anti-fungal activity of FaPR4-C. Furthermore, FaPR4 was detected to have weak but significant chitinase activity, and its chitinase activity was reduced after heat treatment. The chitinase activity by FaPR4-C was much lower than FaPR4.
authors.affiliation: Department of Food Science, Tunghai University, Taichung 407, Taiwan, ROC.
authors.forename: Hsi-Chi
authors.initials: HC
authors.lastname: Lu
authors.forename: Jia-Hui
authors.initials: JH
authors.lastname: Lin
authors.forename: Anna C N
authors.initials: AC
authors.lastname: Chua
authors.forename: Tse-Yu
authors.initials: TY
authors.lastname: Chung
authors.forename: I-Chun
authors.initials: IC
authors.lastname: Tsai
authors.forename: Jason T C
authors.initials: JT
authors.lastname: Tzen
authors.forename: Wing-Ming
authors.initials: WM
authors.lastname: Chou
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology*; D002686:Chitin / Q000378:metabolism*; D002688:Chitinases / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary; D030681:Ficus / Q000737:chemistry*; D005658:Fungi / Q000187:drug effects*; D005670:Fusarium / Q000187:drug effects; D015870:Gene Expression; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010843:Pichia / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D012313:RNA / Q000378:metabolism; D012260:Ribonucleases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry
chemical_list: D000935:Antifungal Agents; D018076:DNA, Complementary; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; D002686:Chitin; D012313:RNA; D012260:Ribonucleases; D002688:Chitinases