title: Tentoxin sensitivity of chloroplasts determined by codon 83 of beta subunit of proton-ATPase.
abstract: Tentoxin is a naturally occurring phytotoxic peptide that causes seedling chlorosis and arrests growth in sensitive plants and algae. In vitro, it inhibits activity of the beta subunit of the plastid proton-adenosine triphosphatase (ATPase) from sensitive species. Plastid atpB genes from six closely related, tentoxin-sensitive or -resistant Nicotiana species differ at codon 83, according to their response to the toxin: glutamate correlated with resistance and aspartate correlated with sensitivity. The genetic relevance of this site was confirmed in Chlamydomonas reinhardtii by chloroplast transformation. The alga, normally tentoxin-resistant, was rendered tentoxin-sensitive by mutagenesis of its plastid atpB gene at codon 83. Codon 83 may represent a critical site on the beta subunit that does not compete with nucleotide binding or other catalytic activities.
authors.affiliation: Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Avni
authors.forename: J D
authors.initials: JD
authors.lastname: Anderson
authors.forename: N
authors.initials: N
authors.lastname: Holland
authors.forename: J D
authors.initials: JD
authors.lastname: Rochaix
authors.forename: Z
authors.initials: Z
authors.lastname: Gromet-Elhanan
authors.forename: M
authors.initials: M
authors.lastname: Edelman
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000595:Amino Acid Sequence; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002696:Chlamydomonas; D002736:Chloroplasts / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000235:genetics; D006868:Hydrolysis / Q000187:drug effects; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009183:Mycotoxins / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology*; D010947:Plants, Toxic; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000502:physiology*; D012247:Rhodospirillum rubrum; D012689:Sequence Homology, Nucleic Acid; D014026:Nicotiana; D014170:Transformation, Genetic
chemical_list: D009183:Mycotoxins; D010456:Peptides, Cyclic; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; C003384:tentoxin