一个能与水稻未成熟种子核蛋白特异结合的31bp的DNA片段

水稻蜡质基因5'上游序列中有5个能与水稻胚乳核蛋白结合的片段，其中HinfId和RsaIe片段有部分重叠，而重叠部分含AACGT顺序。按重叠区上下游顺序合成了其中含有3次重复的AACGT顺序的31bp寡核苷酸，并以此为探针进行凝胶滞后实验，表明它不仅能与未成熟水稻种子的胚乳核蛋白特异结合，而且也与HinfId和RsaIe片段有强烈的竞争作用。因此31bp顺序中含有与水稻胚乳核蛋白专一结合位点，从而有可能应用此31bp的寡核苷酸作探针来分离编码蜡质基因的调控蛋白基因。

A 31 bp DNA Fragment Interacting Specifically with Nuclear Proteins Extracted from Immature Rice Seeds

We reprt here that five fragments (HinfIa-2, HinfIc-1, HinfIc-2,HinfId and RsaIe) in the 5' upstream region of rice ary gene culd interact with nuclear proteins from immature rice seeds (Fig. 1 ). Three cpies of AACGT and several direct and inverted repeat sequences were lcated in the overlapping regin of HinfId and RsaIe DNA fragments in 5' upstream regin of rice ary gene. To test whether this overlapping region contains a nuclear protein-binding site, a 3l bp oligonucletide cntaining three cpies of AACGT and several repeated sequences was synthesized and used as a prbe in gel retardation assays. The results showed that this 31 bp olignucleotides interacted effectively with nuclear proteins extracted frm immature rice seeds (Fig. 2), and competed strongly with unlabeled HinfId and RsaIe fragments (Fig. 3). All these results demonstrate that a specific nuclear prtein-binding site in HinfId and RsaIe is present in the 31 bp DNA fragment, and the finding of nuclear prtein-binding site gave possibility to clone the gene encoding this regulatory prtein using 31 bp DNA fragment as a prbe.