title: Characterization of the carrot beta-tubulin gene coding a divergent isotype, beta-2.
abstract: Four different beta-tubulin clones were isolated from carrot genomic and cDNA libraries. Their nucleotide sequences were determined 1 and their predicted amino acids were compared with each other. The predicted amino acid composition of the C-terminal region of three of them (beta-1, 3, 4) resembled one another, but that of one isotype (beta-2) was divergent. The beta-2 tubulin included two hydroxyl amino acids, serine and threonine, and consisted of a lower number of negatively charged amino acids than the others in the C-terminal region. The predicted hydrophobicity profile of the beta-2 tubulin around the residue 200 is less hydrophobic than beta-1, but it is still more hydrophobic than those of animal and fungal beta-tubulins. The beta-2 gene was transcribed in cultured cells and flowers, while the beta-1 gene was ubiquitously transcribed in cultured cells, roots, shoots and flowers. When the predicted amino acids of plant tubulin were compared with those of other organisms, substitutions from non-polar amino acids to those with hydroxyl group were conspicuous in the region corresponding to the third exon in the plant genes.
authors.affiliation: Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan. okamura@ms.toyama-mpu.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Okamura
authors.forename: K
authors.initials: K
authors.lastname: Naito
authors.forename: S
authors.initials: S
authors.lastname: Sonehara
authors.forename: H
authors.initials: H
authors.lastname: Ohkawa
authors.forename: S
authors.initials: S
authors.lastname: Kuramori
authors.forename: M
authors.initials: M
authors.lastname: Tatsuta
authors.forename: M
authors.initials: M
authors.lastname: Minamizono
authors.forename: T
authors.initials: T
authors.lastname: Kataoka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D010582:Bacteriophage lambda; D001483:Base Sequence; D002460:Cell Line; D018744:DNA, Plant; D018552:Daucus carota / Q000235:genetics*; D015870:Gene Expression; D017343:Genes, Plant; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014404:Tubulin / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D014404:Tubulin