摘要
噬菌体基因组携带多种影响宿主菌生长的基因,是筛选新型抗菌素的可能靶位.本研究分别克隆铜绿假单胞菌(Pseudomonas aeruginosa)噬菌体K4携带的全部75个基因,在阿拉伯糖启动子控制下进行表达.实验结果表明,6个噬菌体基因的表达产物能够显著抑制宿主菌的生长.生物信息学分析显示,基因gp72编码的末端酶大亚基与噬菌体基因组包装过程相关,基因gp49编码假定的5′-3′核酸外切酶,其余4个基因编码产物未发现特定的蛋白结构域.利用脉冲场凝胶电泳分析宿主菌染色体DNA的完整性,在阿拉伯糖诱导5,h时,蛋白Gp17、Gp41、Gp72、Gp29和Gp49能够导致宿主菌染色体DNA的显著降解,这是抑制宿主菌生长的可能原因.蛋白Gp67对宿主菌染色体DNA没有影响,其抑制细胞生长的机制不同于其他蛋白.实验还发现,筛选基因的产物还能影响噬菌体的感染效率.本研究发现的抑制细菌生长的基因,能够为筛选新型抗菌素提供新的靶位.
Phage genes might inhibit the growth of host bacteria and are likely the targets for novel antibiotics screening.In this research,all 75,genes of Pseudomonas aeruginosa phage K4,were cloned and expressed under the control of arabinose promoter,respectively.Six of them might inhibit the growth of the host bacteria.Bioinformatic analysis showed that gene gp72 encodes a terminase large subunit relating to phage genome packaging process;gene gp49 encodes a hypothetical 5＇-3＇ exonuclease;and the remaining four genes encode hypothetical proteins with unknown functional domains.Pulsed field gel electrophoresis was used in analyzing the chromosome DNA extracted from the host cells carrying the identified genes.After arabinose induction for 5 h,the strains expressing protein Gp17,Gp41,Gp72,Gp29,and Gp49,respectively,had their genome DNA degraded significantly,and the possible cause is that the growth of the host had been inhibited.No genome DNA degradation was observed in protein Gp67,indicating a different inhibition mechanism might be employed by the gene product.Our data also show that the products of the isolated genes might affect the infection efficiency of the phage.In conclusion,the genes identified in our work inhibiting the growth of the bacteria may serve as new targets for screening novel antimicrobial agents.
作者
周维
孙利
尤甲甲
杨洪江
ZHOU Wei;SUN Li;YOU Jiajia;YANG Hongjiang(Key Laboratory of Industrial Fermentation Microbiology,Ministry of Education,Tianjin Key Laboratory of Industrial Microbiology,College of Biotechnology,Tianjin University of Science ＆ Technology,Tianjin 300457,China)
出处
《天津科技大学学报》
CAS
2018年第4期7-13,共7页
Journal of Tianjin University of Science & Technology
基金
国家自然科学基金资助项目(31370205
30970114)
