(1. 中南大学 资源加工与生物工程学院，长沙 410083；
2. 中南大学 教育部生物冶金重点实验室，长沙 410083)
摘 要: 鉴定了Acidithiobacillus ferrooxidans DC (At. ferrooxidans DC)中与锌离子转运相关的4个ATP-binding cassette (ABC) transporter基因，并采用Reverse Transcription quantitative real-time PCR (RT-qPCR)技术分析在不同浓度的锌离子胁迫下这4个ATP-binding cassette (ABC) transporter基因在转录水平上的差异表达情况。然后利用Vector NTI、cluster X、BLAST、ORF Finder等生物信息学软件对各基因做进一步的生物信息学分析。结果表明：在锌离子胁迫下，4个ABC transporter基因(AFE_2435、AFE_2436、AFE_2437、AFE_2438)的表达量均有所上调，说明这4个基因对于锌离子的胁迫具有很强的敏感性。经生物信息学分析可知，基因AFE_2435和AFE_2436编码位于细胞质膜上的透性酶，AFE_2437编码位于细胞质膜上的ATP结合蛋白，AFE_2438编码位于周质空间的锌离子结合蛋白，这4个基因共同组成了一个与锌离子转运有关的ABC转运子。这些结果都表明这4个ABC transporter基因与DC菌中锌离子的转运有着密切的关系。
关键字: 嗜酸氧化亚铁硫杆菌；ABC transporter；RT-qPCR；锌离子胁迫；生物信息学分析
（1. School of Minerals Processing and Bioengineering, Changsha 410083, China;
2. Key Laboratory of Biometallurgy, Ministry of Education, Central South University, Changsha 410083, China）
Abstract:In this study, four ATP-binding cassette (ABC) transporter genes of Acidithiobacillus ferrooxidans DC (At. ferrooxidans DC) were identified, and differential transcription of these genes during zinc ion stress were investigated by Reverse Transcription quantitative real-time PCR (RT-qPCR). And then, the genes involved in zinc ion transport were analyzed by bioinformatics software. The results show that the expressions of the four ABC transporter genes are increased differently under zinc ion stress, indicating that these genes are sensitive to zinc levels. Bioinformatics analysis shows that the proteins encode by AFE_2435, AFE_2436 are predicted to be permease proteins, whereas the protein encode by AFE_2437 is a putative ATP-bindind protein and AFE_2438 encoded a putative periplasmic cation-binding protein. The four genes together form an ABC transporter for zinc ion transport. These results strongly suggest that the four ABC transporter genes might be directly involved in zinc transport in Acidithiobacillus ferrooxidans DC.
Key words: Acidithiobacillus ferrooxidans; ABC transporter; RT-qPCR; zinc ion stress; bioinformatics analysis
