title: Direct molecular cloning and expression of two distinct abrin A-chains.
abstract: The protein toxin abrin, which possesses an N-glycosylase activity toward eukaryotic 28 S rRNA, may have a potential in the deliberate eradication of certain cells. Here we report, by polymerase chain reaction technique, the isolation of genomic DNA sequences encoding two distinct abrin A-chains. A third sequence which encoded a part of a third type of A-chain was also isolated. The deduced amino acid sequences of the two full-length A-chains were about 84% similar. Addition of mRNA encoding the full-length A-chains to reticulocyte lysate strongly inhibited protein synthesis in the lysates, and a corresponding glycosylase activity on rRNA was observed. Addition of the same mRNA to toxin-resistant wheat germ extracts led to synthesis of the expected 30-kDa protein which could be precipitated with antibodies specific for abrin.
authors.affiliation: Apothekernes Laboratorium A.S., Oslo, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Evensen
authors.forename: A
authors.initials: A
authors.lastname: Mathiesen
authors.forename: A
authors.initials: A
authors.lastname: Sundan
mesh_terms: D000036:Abrin / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D015870:Gene Expression; D014644:Genetic Variation; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping
chemical_list: D046911:Macromolecular Substances; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D000036:Abrin