Two genes encoding 1-aminocyclopropane-1-carboxylate synthase in zucchini (Cucurbita pepo) are clustered and similar but differentially regulated.
Two genes encoding 1-aminocyclopropane-1-carboxylate synthase in zucchini (Cucurbita pepo) are clustered and similar but differentially regulated.
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DOI：
10.1073/pnas.88.16.7021
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发表时间：
1991-08
影响因子：
11.1
通讯作者：
P. Huang;J. Parks;W. Rottmann;A. Theologis
中科院分区：
文献类型：
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作者：
P. Huang;J. Parks;W. Rottmann;A. Theologis
西葫芦（Cucurbita pepo）基因组的17-腺苷酸酶（kb）区域已被测序，并且包含编码1-氨基环丙烷-1-羧酸合酶（ACC合酶; S-腺苷-L-甲硫氨酸甲硫腺苷-裂解酶，EC 4.4.1.14）的两个基因CP-ACC 1A和CP-ACC 1B。这些基因的转录是收敛的，并由一个5.7 kb的基因间区分开。它们的编码区被位于相同位置的四个内含子中断。虽然它们编码区的DNA同一性为97%，但它们的5'和3'侧翼区高度不同。CP-ACCIA的转录在果实和黄化的下胚轴中被创伤快速诱导，并且仅在果实组织中被吲哚乙酸（IAA）/苄基腺嘌呤/LiCl诱导。尚未发现诱导CP-ACC 1B表达的条件。蛋白质合成抑制使CP-ACC 1A和其他未鉴定的ACC合酶基因的表达去抑制，表明它们可能处于负控制下。从基因的核苷酸序列推导的氨基酸序列为493和494个残基长，具有95%的同一性。氨基酸序列的最显著特征是存在12个不变氨基酸残基中的11个，这些氨基酸残基参与各种转氨酶中底物和吡哆醛-5 '-磷酸的结合。我们的结论是ACC合酶编码的多基因家族的某些成员差异诱导生长素在组织特异性的方式。此外，ACC合成酶，含吡哆醛的酶，可能有一个进化的关系，与超家族的转氨酶。
A 17-kilobase (kb) region of the zucchini (Cucurbita pepo) genome has been sequenced and contains two genes, CP-ACC1A and CP-ACC1B, encoding 1-aminocyclopropane-1-carboxylate synthase (ACC synthase; S-adenosyl-L-methionine methylthioadenosine-lyase, EC 4.4.1.14). The genes are transcribed convergently and are separated by a 5.7-kb intergenic region. Their coding regions are interrupted by four introns located in identical positions. While the DNA identity in their coding regions is 97%, their 5' and 3' flanking regions are highly divergent. Transcription of CP-ACCIA is rapidly induced by wounding in fruit and etiolated hypocotyls and by indoleacetic acid (IAA)/benzyladenine/LiCl only in fruit tissue. Conditions that induce CP-ACC1B expression have not been found. Protein synthesis inhibition derepresses the expression of CP-ACC1A and other unidentified ACC synthase genes, suggesting that they may be under negative control. The amino acid sequences deduced from the nucleotide sequences of the genes are 493 and 494 residues long with 95% identity. The most notable feature of the amino acid sequence is the presence of 11 of the 12 invariant amino acid residues involved in the binding of the substrate and pyridoxal-5'-phosphate in various aminotransferases. We conclude that ACC synthase is encoded by a multigene family of which certain members are differentially induced by auxin in a tissue-specific manner. Furthermore, ACC synthase, a pyridoxal-containing enzyme, may have an evolutionary relationship with the superfamily of aminotransferases.