Zhu Lin, Deng Wei-Wei, Ye Ai-Hua, Yu Mei, Wang Zhao-Xia, Jiang Chang-Jun
Key Laboratory of Tea Biochemistry and Biotechnology, Ministry of Education and Ministry of Agriculture, Anhui Agricultural University of China, Hefei, Anhui 230036, China.
Plant Physiol Biochem. 2008 Aug-Sep;46(8-9):731-8. doi: 10.1016/j.plaphy.2007.03.029. Epub 2007 Apr 5.
ATP sulfurylase, the first enzyme in the sulfate assimilation pathway of plants, catalyzes the formation of adenosine phosphosulfate from ATP and sulfate. Here we report the cloning of two cDNAs encoding ATP sulfurylase (APS1 and APS2) from Camellia sinensis. They were isolated by RT-PCR and RACE-PCR reactions. The expression of APS1 and APS2 are correlated with the presence of ATP sulfurylase enzyme activity in cell extracts. APS1 is a 1415-bp cDNA with an open reading frame predicted to encode a 360-amino acid, 40.5kD protein; APS2 is a 1706-bp cDNA with an open reading frame to encode a 465-amino acid, 51.8kD protein. The predicted amino acid sequences of APS1 and APS2 have high similarity to ATP sulfurylases of Medicago truncatula and Solanum tuberosum, with 86% and 84% identity respectively. However, they share only 59.6% identity with each other. The enzyme extracts prepared from recombinant Escherichia coli containing Camellia sinensis APS genes had significant enzyme activity.
ATP硫酸化酶是植物硫酸盐同化途径中的首个酶，催化由ATP和硫酸盐形成腺苷磷酸硫酸。在此，我们报道了从茶树中克隆出两个编码ATP硫酸化酶的cDNA（APS1和APS2）。它们通过逆转录聚合酶链反应（RT-PCR）和快速扩增cDNA末端聚合酶链反应（RACE-PCR）分离得到。APS1和APS2的表达与细胞提取物中ATP硫酸化酶的酶活性存在相关。APS1是一个1415碱基对的cDNA，其开放阅读框预计编码一个360个氨基酸、40.5千道尔顿的蛋白质；APS2是一个1706碱基对的cDNA，其开放阅读框编码一个465个氨基酸、51.8千道尔顿的蛋白质。APS1和APS2预测的氨基酸序列与蒺藜苜蓿和马铃薯的ATP硫酸化酶具有高度相似性，分别具有86%和84%的同一性。然而，它们彼此之间的同一性仅为59.6%。从含有茶树APS基因的重组大肠杆菌制备的酶提取物具有显著的酶活性。
