关键词: 苏云金芽胞杆菌, aiiA基因, 密码子偏好性, 密码子优化, 异源表达

Abstract: AiiA, encoded by aiiA gene is one of the homoserine lactone enzyme that can hydrolyze the AHL on the lactone ring of Gram-negative bacteria. Coding sequence of aiiA gene from Bacillus thuringiensis was analyzed by CodonW, CUSP and CHIPS programs for identifying codon bias. Comparing the codon usage of aiiA gene with genomic codon usage of Escherichia coli, Bacillus thuringiensis, Bacillus subtilis and Pichia pastoris, it was indicated that aiiA gene prefers to use the codons ended with A or T; codon bias of aiiA gene from Bacillus thuringiensis was significantly different from those of E.coli, Bacillus subtilis and Pichia pastoris. The result of comparing the usage frequency of aiiA gene in four different hosts showed that there were different degrees of low frenquency regions. The analytic result was very important guideline for designing the aiiA gene to improve the expression of AiiA in those four express systems.

Key words: Bacillus thuringiensis, aiiA gene, codon usage bias, codon optimization, heterogeneous expression