【摘要】 通过PCR的方法从Bacillussubtilis基因组中克隆了中性植酸酶基因nphy ,DNA全序列分析表明其结构基因全长 115 2个核苷酸 (编码 383个氨基酸 ) ,5′端有一编码 2 6个氨基酸的信号肽序列。去除信号肽编码序列的nphy克隆到大肠杆菌IPTG诱导表达载体pTYB40上 ,在大肠杆菌中得到了高效表达 ,表达量达到大肠杆菌可溶性蛋白的 40 %以上 ,表达产物具有生物学活性 ,证实了克隆到的中性植酸酶的编码基因有正常的生物学功能。更多还原

【Abstract】 The gene encoding the neutral phytase nphy was cloned from Bacillus subtilis by polymerase chain reaction(PCR). Nucleotide sequence analysis of nphy revealed the presence of an open reading frame of 1152 bp coding for 383 aa. The start codon was followed by a sequence coding for a putative signal peptide of 26 aa in length. The nphy without original signal peptide encoding sequence was cloned into E.coli expression plasmid pTYB40. The result of SDS PAGE of the phytase expressed in E.coli showed that the nphy had been overexpressed. The expressed phytase was over 40% of the total soluble protein of E.coli ,and has normal bioactivity.更多还原