Abstract：
As the only translational factor that plays a critical role in two translational processes (elongation and ribosome regeneration), GTPase elongation factor G (EF-G) is a potential target for antimicrobial agents. Both Mycobacterium smegmatis and Mycobacterium tuberculosis have two EF-G homologous coding genes, MsmEFG1 (MSMEG_1400) and MsmEFG2 (MSMEG_6535), fusA1 (Rv0684) and fusA2 (Rv0120c), respectively. MsmEFG1 (MSMEG_1400) and fusA1 (Rv0684) were identified as essential genes for bacterial growth by gene mutation library and bioinformatic analysis. To investigate the biological function and characteristics of EF-G in mycobacterium, two induced EF-G knockdown strains (Msm-ΔEFG1(KD) and Msm-ΔEFG2(KD)) from Mycobacterium smegmatis were constructed by clustered regularly interspaced short palindromic repeats interference (CRISPRi) technique. EF-G2 knockdown had no effect on bacterial growth, while EF-G1 knockdown significantly retarded the growth of mycobacterium, weakened the film-forming ability, changed the colony morphology, and increased the length of mycobacterium. It was speculated that EF-G might be involved in the division of bacteria. Minimal inhibitory concentration assay showed that inhibition of EF-G1 expression enhanced the sensitivity of mycobacterium to rifampicin, isoniazid, erythromycin, fucidic acid, capreomycin and other antibacterial agents, suggesting that EF-G1 might be a potential target for screening anti-tuberculosis drugs in the future.
摘要：
作为在两个翻译过程（延伸和核糖体再生）中起关键作用的唯一翻译因子，GTP酶延伸因子G（EF-G）是抗微生物剂的潜在靶标。耻垢分枝杆菌和结核分枝杆菌都有两个EF-G同源编码基因，MsmEFG1(MSMEG_1400)和MsmEFG2(MSMEG_6535)，fusA1(Rv0684)和fusA2(Rv0120c)，分别。MsmEFG1（MSMEG_1400）和fusA1（Rv0684）通过基因突变文库和生物信息学分析被鉴定为细菌生长的必需基因。探讨分枝杆菌EF-G的生物学功能和特性,通过成簇规则间隔的短回文重复干扰（CRISPRi）技术，构建了来自耻垢分枝杆菌的两个诱导的EF-G敲低菌株（Msm-ΔEFG1（KD）和Msm-ΔEFG2（KD））。EF-G2敲除对细菌生长没有影响,而EF-G1基因敲低显著延缓了分枝杆菌的生长,削弱了成膜能力，改变了菌落的形态,并增加了分枝杆菌的长度。推测EF-G可能参与细菌的分裂。最低抑菌浓度测定显示,抑制EF-G1的表达可增强分枝杆菌对利福平的敏感性,异烟肼,红霉素,岩藻酸，卷曲霉素和其他抗菌剂，提示EF-G1可能是未来筛选抗结核药物的潜在靶点.
