侧耳木霉T2-1植酸酶基因的序列分析及蛋白结构预测

Gene Sequencing and Protein Tertiary Structure Predicting of Phytase from Trichoderma pleuroticola Isolate T2-1

利用GenBank发表的植酸酶A编码序列设计的引物,通过PCR的方法对侧耳木霉(Trichoderma pleuroticola)T2-1基因组DNA进行扩增,获得了一条长约1.7 kb的特异性DNA片段。序列测定结果表明,该DNA片段含有植酸酶编码基因的完整序列和3段内含子序列,其中植酸酶基因全长1 443 bp,编码480个氨基酸,5'端有一段编码23个氨基酸的信号肽序列,其余的457个氨基酸残基为成熟植酸酶的氨基酸序列。对该基因编码的氨基酸序列进行三级结构预测,发现它为磷酸单酯酶。已将侧耳木霉T2-1植酸酶基因序列在GenBank中注册(登录号:GQ325590)。这是目前中国在GenBank注册的第一个完整的木霉植酸酶编码基因。

We amplified a 1.7 kb DNA fragment from genomic DNA of Trichoderma pleuroticola T2-1 by the polymerase chain reaction（PCR）technology with primers designed according to the sequences of the phytase A gene in GenBank.DNA sequencing showed that the fragment contained the whole 1 443 bp coding sequence of phytase gene and three introns.The gene encoded a peptide of 480 amino acid residues,in which there is a signal peptide with 23 amino acids at the 5′end and the left 447 amino acids are the mature peptide sequences.Tertiary structure prediction for its protein product showed that it was a phosphomonoesterase,and the phytase gene of Trichoderma pleuroticola T2-1 had been registered in the GenBank（accession number：GQ325590）.In summary,we had cloned a novel gene and the phytase is the first integrated phytase encode gene of Trichoderma registered in the GenBank in China.