关键词: 同源建模, 植酸酶基因, 克隆

Abstract: The full-length DNA sequence of neutral phytase gene was cloned from Bacillus amyloliquefaciens DSM 1061 by PCR, and successfully inserted into the expression vector pET22b(+). The results were identified by PCR and DNA sequencing. Based on Blast alignment, it was found that the amino acid sequence of the enzyme has never been reported the Swiss-prot database. Its amino acids sequence showed 98.7% identity with that of Bacillus subtilis (Swiss-prot ID: O31097). The residues 128, 144, 153, 257 and 370 are replaced by Ala, Ile, Ser, Pro and Lys, respectively. The N-terminal residues 1—26 were predicted to be a signal peptide by Signal P 3.0 Server. The homology modeling of the new phytase was constructed using SWISS-MODEL. The software PROCHECK V3.5 was used to evaluate the model according to Ramachandran plot and G-factor. The results showed that the bond length, bond angle, the distribution of dihedral angle and structure were rational. The gene sequence has been submitted to the NCBI GenBank and the accession number is HM 747163.

Key words: phytase gene, cloning, homology modeling