γ-聚谷氨酸的基因克隆与序列分析  

Gene Cloning and Sequence Analysis of Poly-γ-Glutamic Acid

作　　者：吉美萍 那日[1] 郭九峰[1] 肖志婷[2] 庞艳波[1] 付丽丽[1] 

机构地区：[1]内蒙古大学物理科学与技术学院自治区离子束生物工程重点实验室,呼和浩特010021 [2]内蒙古农业大学理学院,呼和浩特010018

出　　处：《基因组学与应用生物学》2017年第6期2417-2429,共13页Genomics and Applied Biology

基　　金：国家自然科学基金(51267014)高压电晕电场对微生物诱变效应的研究(30101-131135)资助

摘　　要：本研究通过基因组DNA提取和PCR扩增分别得到Bacillusnatto20646的原初始菌株N-1、高压电晕电场和不同种类稀土元素诱变的突变株N-2、N-3、N-4、N-5及N-6的pgsBCA合成酶基因序列,利用BioEdit软件对6株菌株的pgsB、pgsC和pgsA的基因序列及合成酶蛋白PgsB、PgsC和PgsA蛋白酶的氨基酸序列对比后得出:pgsB、pgsC和pgsA基因分别约含1170个、450个和1140个核苷酸,分别编码约390个、150个和380个氨基酸。高压电晕电场和稀土元素使得菌株γ-PGA合成酶基因簇pgsBCA核苷酸发生了碱基的置换和颠换、插入和缺失,合成酶蛋白PgsBCA氨基酸序列发生了氨基酸的替换、插入和缺失,且对序列的开端和尾端的影响较大,PgsA在30~40个氨基酸区间变化显著,使该处氨基酸残基的跨膜区发生变化,准确的膜锚定,γ-PGA高效地从活性中心位点移开,加快实现了链的延长,为γ-PGA产量的提高提供理论基础。We obtained initial bacterial N-lof Bacillus natto20646, high-voltage corona field and mutant strain N-2, N-3, N-4, N-5 induced by different rare earth elements by DNA extracting, and obtained the pgsBCA synthetase＇s sequence of N-6 by PCR. Their pgsBCA synthase gene sequences were obtained by genomic DNA extraction and PCR amplification. The sequences ofpgsB, pgs C and pgsA and the amino acid sequences of PgsB, PgsC and PgsA protease of 6 strains were compared and analyzed by the software of BioEdit. The results showed that the pgsB, pgsC and pgsA genes contained about 1 170, 450 and 1 140 nucleotides, and encoded about 390, 150 and 380 amino acids, respectively. The high-voltage corona electric field and rare-earth element mutagenesis resulted in substitution, transversion, insertion and deletion of rib otide in nucleotide sequences of the γ-PGA synthase gene cluster pgsBCA, and resulted in the substitution, insertion and deletion in amino acids in the synthetase protein PgsBCA. There was a large effect on the start and end of the sequence. The PgsA changed significantly in the range of 30-40 amino acids, which resulted in the transmembrane region of the amino acid residues changing, the accurate membrane anchoring, γ-PGA moving away from the active site efficiently, and the extension of the chain accelerating. It provided a theoretical basis for improving the production of-FPGA.

关 键 词：Γ-PGA γ-PGA合成酶 pgsBCA 序列对比 

分 类 号：Q78[生物学—分子生物学]