Biosynthesis of thiamin-binding proteins in developing sesame seeds
The formation of thiamin-binding proteins (TBPs) from sesame (<i>Sesamum indicum</i> L.) seeds (STBP-I, -II and -III) in developing seeds was investigated. Elution profiles of STBPs obtained from seeds at 4 to 6 weeks after flowering from the Q-Sepharose Fast Flow column showed that only one STBP was contained in the seeds at 4 weeks, and two STBPs were contained in the seeds at 5 weeks, and all three STBPs were contained in the seeds at 6 weeks as well as in mature seeds. SDS-PAGE of those STBPs demonstrated that STBP in the seeds at 4 weeks was large STBP termed as STBP-III, the molecular mass of which was higher than STBP-I and -II. In addition, it was demonstrated that small and large STBPs were contained in the seeds at 5 weeks, and STBP-I, -II and -III were contained in the seeds at 6 weeks. On the other hand, Southern blot analysis of digested genomic DNAs from sesame leaves with an <i>STBP</i> cDNA probe indicated the presence of only one copy of <i>STBP</i> in the sesame genome. These results suggested that STBP-III was first produced from a large proprotein precursor in developing sesame seeds, and STBP-I and -II were produced from the same polypeptide chain by different types of post-translational processing.
- Plant biotechnology
Plant biotechnology 24(3), 331-334, 2007-06-01
Japanese Society for Plant Cell and Molecular Biology