溶藻弧菌质粒pVAE259全序列测定与分子生物学特征分析

Complete nucleotide sequence of a plasmid pVAE259 from Vibrio alginolyticus and analysis of molecular biological characteristic of the plasmid

摘要:

摘要：【目的】获得溶藻弧菌环状质粒pVAE259全序列，分析其分子生物学特征并探索该质粒可能具备的功能。【方法】使用酶切、克隆测序的方法获得pVAE259的全序列，利用软件分析DNA序列和可能的编码蛋白，推测质粒的生物学信息。【结果】pVAE259为闭合环状质粒，全长6,075 bp，GC含量为42.16%。在NCBI中比对发现pVAE259与Vibrio sp. 41隐蔽性质粒pPS41具有较高的相似性。我们在序列中找到一个oriT位点，另外全序列的4118-5494 bp推测为质粒复制区域。pVAE259中存在7个氨基酸序列长度大于100的开放式阅读框（ORF）：ORF1-ORF7。其中ORF1编码蛋白属于释放酶超级家族（Relaxase Super-family）蛋白，在NCBI数据库中它与大肠杆菌（Escherichia coli）的MobA-like蛋白最相似；ORF2编码蛋白属于复制酶超级家族（Replicase Super-family），它与嗜麦芽寡养单胞菌（Stenotrophomonas maltophilia）的复制蛋白RepA最相似；ORF5与伸长盐单胞菌（Halomonas elongata）质粒pHE1的转移蛋白MobC相似。【结论】根据上述结果及相关文献分析，pVAE259可能是具有转移能力的质粒，该质粒是否影响宿主菌的表型性状还不清楚。

Abstract:

Abstract: [Objective]To obtain the complete nucleotide sequence of the plasmid pVAE259 from Vibrio alginolyticus, to analyze molecular characteristic of the plasmid, and to explore its potential function. [Methods]We got the whole sequence of pVAE259 by the steps including of enzyme digestion, cloning, analysis of the acquired sequence and putative encoded protein using the softwares followed by speculation of its potential biological function.[Results] pVAE259 was a covalently closed circular plasmid. The complete sequence consists of 6075 bp in length, with a 42.16% GC content, and it is similar to the crytic plasmid pPS41 of Vibrio sp. 41. There is an origin of transfer (oriT) region in the sequence and a replication region located in the part from 4118 to 5494 bp. Seven open reading frames that longer than one hundred amino acids were found in pVAE259, ORF1-ORF7. The protein encoded by ORF1 should be classed into the members of relaxase superfamily, which is closest related to the MobA-like protein of Escherichi coli. The protein encoded by ORF2 should be classed into the members of the replicase superfamily, which is closest related to the protein RepA of Stenotrophomonas maltophilia. The protein encoded by ORF5 is similar to the protein MobC in the plasmid pHE1 of Heliamphora longata. [Conclusion] The plasmid pVAE259 might have the ability to transfer between different bacterial strains.