| Amino acid compositions of ferredoxins isolated from
common wheat and the relatives Masateru SHIN, Zen-ichi YOKOYAMA* and Hirosuke FUKASAWA Department of Biology, Faculty of Science, Kobe University and *Kobe Yamate Women's College, Kobe, Japan Plant-type ferredoxin is a low molecular, iron-sulfur protein and functions as an electron carrier in the fundamental metabolisms of plants, such as photosynthesis and nitrate assimialtion. They distributed in a wide taxonomical range from higher plants to blue-green algae. Because of these situations of ferredoxin, the protein has been considered to be a particularily suitable component to study on the biochemical evolution of plants. Matsubara and his colleagues (MATSUBARA et al., 1978, WAKABAYASHI et al., 1978) have investigated primary structures of ferredoxins isolated from many plants, including from higher plants to blue-green algae, and proposed the phylogenetic tree of ferredoxin. On the other hand, KIHARA (KIHARA, 1924. KIHARA and LILIENFELD, 1949) has established that common wheat, possessing genome complement of AABBDD, is originated as an amphidiploid of a hybrid between a species of emmer wheat (AABB) and Aegilops squarrosa (DD). It is, therefore, of considerable interest to study whether the genealogical relationships in wheat plants bring any change on the chemical composition of ferredoxin in these plants. For the present interest, amino acid compositions were analyzed for ferredoxins isolated from three species of Triticum, T. aegilopoides var. boeoticum, T. durum ver. apulicum, and T. aestivum cultvar. Shirasagi, and two of Aegilops, Ae. squarrosa var. typica and Ae.ovata. as shown in Table 1. The analysis data appear to indicate that these five ferredoxins are all idintical. For comparing with other ferredoxins, amino acid composition of Hordeum vulgare is also shown in the same table. Differences can be seen in the contents of glutamic acid, valine, isoleucine and leucine. It is, therefore, likely that one molecular species of ferredoxin is distributed through two genera of Triticum and Aegilops, and that ferredoxin molecule has remained unaltered during the evolution of wheat plants. References KIHARA, H. 1924. Cytologishe und genetishe Studien bei wichtigen Getreidearten mit besonderer Rucksicht auf das Verhalten der Chromosomen und die Sterilitat in den Bastarden. Mem. Coll. Sci. Kyoto Imp. Univ. 1: 1-200 KIHARA, H. and F. LILIENFELD 1949. A new synthesized wheat. Proc. VIIIth Internatl. Cong. Genet. (Hereditas, Suppl.) 307-319 MATSUBARA, H., T. HASE, S. WAKABAYASHI and K. WADA 1978. Gene duplications during evolution of chloroplast-type ferredoxins. in Evolution of Protein Molecules (Matsubara, H. and T. Yamanaka eds.) pp 209-219 SHIN, M., Z. YOKOYAMA, A. ABE and F. FUKASAWA 1979. Properties of common wheat ferredoxin, and a comparison with ferredoxin from the related species of Triticum and Aegilops. J . Biochem. (in press) WAKABAYASHI, S., T. HASE, K. WADA, H. MATSUBARA. K. SUZUKI, and S. TAKAICHI 1978. Amino acid sequences of two ferredoxins from pokeweed, Phytolacca americana J. Biochem 83: 1305-19 13 |
| Remark: This work was supported in part by a grant (No. 312107, 1978) from the Ministry of Education, Science and Culture of Japan. |