title: Cloning and characterisation of a gene encoding an antiviral protein from Clerodendrum aculeatum L.
abstract: The Clerodendrum aculeatum-systemic resistance inducing (CA-SRI) protein, a 34 kDa basic protein, plays a key role in inducing strong systemic resistance in susceptible plants against various plant viruses [22]. We have cloned the cDNA encoding the CA-SRI from C. aculeatum leaves using antibodies raised against the purified protein and degenerate oligonucleotide probes derived from microsequencing of the CA-SRI protein. The full-length cDNA consisted of 1218 nucleotides with an open reading frame of 906 bp. The deduced amino acid sequence of CA-SRI protein showed varying homology (ranging from 11 to 54%) to the ribosome inactivating proteins (RIPs) from other plant species. CA-SRI inhibited in vitro protein synthesis both in rabbit reticulocyte lysate and wheat germ lysate but not in Escherichia coli in vitro translation system. The CA-SRI open reading frame was expressed in an E. coli expression vector and the purified recombinant protein inhibited protein synthesis in rabbit reticulocyte lysate. Southern blot analysis indicated that the CA-SRI gene may be present in low copy number.
authors.affiliation: International Centre For Genetic Engineering and Biotechnology, New Delhi, India.
authors.forename: D
authors.initials: D
authors.lastname: Kumar
authors.forename: H N
authors.initials: HN
authors.lastname: Verma
authors.forename: N
authors.initials: N
authors.lastname: Tuteja
authors.forename: K K
authors.initials: KK
authors.lastname: Tewari
mesh_terms: D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D003001:Cloning, Molecular; D004305:Dose-Response Relationship, Drug; D017343:Genes, Plant; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D010935:Plant Diseases; D018515:Plant Leaves / Q000737:chemistry; D010940:Plant Proteins / Q000235:genetics* / Q000494:pharmacology; D010942:Plant Viruses / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects*; D011994:Recombinant Proteins / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid
chemical_list: D000998:Antiviral Agents; C105270:CA-SRI protein, Clerodendrum aculeatum; D010940:Plant Proteins; D011994:Recombinant Proteins