Nakayama H, Komatsu S, Namai H, Okuno K
National Institute of Agrobiological Resources, Ibaraki, Japan.
Genes Genet Syst. 1999 Dec;74(6):309-14. doi: 10.1266/ggs.74.309.
N-terminal amino acid sequences of six prolamins encoded by seven alleles at two loci, Pro1 and Pro2, of foxtail millet (Setaria italica (L.) P. Beauv.) were analyzed and compared with other prolamins of subfamily Panicoideae. Based on the N-terminal amino acid sequences, band 3 (the prolamin purified from band 3) which is controlled by an allele at the Pro1 locus and bands 1, 2, 4, 5 and 6 which are controlled by alleles at the Pro2 locus could be classified into three groups. Band 3 was found to be homologous to the prolamin of pearl millet (Pennisetum americanum) and is designated as the "pennisetin-like prolamin". Bands 2 and 4, and bands 1, 5 and 6 were subdivided into "x-type prolamin" and "y-type prolamin". Both of the x-type and y-type prolamins showed homology with prolamin of Echinochloa crus-galli and alpha-zein-like prolamins of maize, sorghum and Job's tears. Therefore, these prolamins were designated as "alpha-zein-like prolamin". These results suggest that alleles at the Pro1 locus and those at the Pro2 locus have not arisen from an identical ancestral gene, and that the Pro2 locus comprise two tightly linked genes, which encode similar prolamins. Hypotheses on the diversification of alleles at the Pro2 locus are discussed based on the N-terminal amino acid sequences of the respective bands, combinations of bands controlled by the alleles, and frequencies of the alleles.
对谷子（Setaria italica (L.) P. Beauv.）两个位点Pro1和Pro2上7个等位基因编码的6种醇溶蛋白的N端氨基酸序列进行了分析，并与黍亚科的其他醇溶蛋白进行了比较。根据N端氨基酸序列，由Pro1位点的一个等位基因控制的带3（从带3中纯化的醇溶蛋白）以及由Pro2位点的等位基因控制的带1、2、4、5和6可分为三组。发现带3与珍珠粟（Pennisetum americanum）的醇溶蛋白同源，被命名为“类狼尾草醇溶蛋白”。带2和4，以及带1、5和6被细分为“x型醇溶蛋白”和“y型醇溶蛋白”。x型和y型醇溶蛋白均与稗草的醇溶蛋白以及玉米、高粱和薏苡的α-玉米醇溶蛋白样醇溶蛋白具有同源性。因此，这些醇溶蛋白被命名为“α-玉米醇溶蛋白样醇溶蛋白”。这些结果表明，Pro1位点的等位基因和Pro2位点的等位基因并非来自同一个祖先基因，并且Pro2位点包含两个紧密连锁的基因，它们编码相似的醇溶蛋白。基于各条带的N端氨基酸序列、由等位基因控制的条带组合以及等位基因频率，讨论了Pro2位点上等位基因多样化的假说。
