芒果AP1同源基因的克隆及其生物信息学分析

Cloning and Bioinformatic Analysis of the AP1 Homolog Gene from Mango

我们采用RT-PCR方法克隆了2个A州同源基因全长cDNA，分别命名为MAPl—1（GenBankac—cession No．FJ529206）和MAPl—2（GenBankaccession No．FJ529207）。MAPl—1编码247个氨基酸，开放阅读框长度为741bp，蛋白质分子量为28．54kD，等电点为8．31；MAPl—2编码248个氨基酸，开放阅读框长度为744bp，蛋白质分子量为28．78kD，等电点为8．70。同源性分析表明，它们的核苷酸序列与其它木本植物A纠同源基因的一致性为72％～81％。实验分析表明，MAPl—1和MAPl—2第1至第61个氨基酸含有一个MADS盒结构域，第88至第178个为K盒结构域；两个基因均定位于细胞核，且功能位点分布存在着不同，推测这两个基因在花器官发育过程中的功能存在差异。蛋白二级结构预测显示，MAPl—1蛋白有12个α-螺旋，4个8折叠区，14个β-转角；而MAP1—2蛋白有11个α-螺旋，5个B折叠区，15个β-转角；其大多数氨基酸具有亲水性。本研究有助于进一步了解芒果的开花分子机理及成花的生物学发育阶段。

In this paper, we cloned two full-length eDNA sequences of homologous gene A Pl by employing RT-PCR, which named as MAP1-1 and MAP1-2. The accession number at GenBank are FJ529206 and FJ529207, respectively. The MAP 1-1 contains an 741 bp open reading frame （ORF） corresponding to a deduced protein of 248 amino acids, while the estimated molecular weight and isoelectric point of the putative protein were 28.54 kD and 8.31. The MA P1-2 with a open reading frame （ORF） of 744 bp, encoding 248 amino acid with a predicted molecular mass of 28.78 kD and a pI of 8.70. A comparison of the deduced amino acid residues indicated that their nucleotide sequences have a range of 72% to 81% identities with A Pl gene homologues of other woody plants. The experimental results indicated that MAPI-1 and MAP1-2 had MADS-box region between the 1st and 61th amino acid and K-box region between the 88th and 178 th amino acid. Both genes were located in the nucleus, however, the distribution of functional positions was different between these two genes which may cause different behavior during the growth of floral organ. Prediction of the secondary structure of the protein showed that MAPl-1 protein had 12 α helix, 4 13 sheet and 14 13 turn, while MAP1-2 protein had 11 α helix, 5 β sheet and 15 β turn. Most of the amino acids were observed to be hydrophilic. The research was benefitial to the further understanding of the molecular mechanism of flowering and biological developmental stages of flowering.