Identification and Characterization of hmr19 Gene Encoding a Multidrug Resistance Efflux Protein from Streptomyces hygroscopicus subsp.yingchengensis Strain 10-22  

作　　者：LeiQIN Heng-AnWANG Zhong-QinWU Xiao-FengZHANG Mei-LeiJIN Zi-XinDENG Guo-PingZHAO 

机构地区：[1]ShanghaiResearchCenterofBiotechnology,ShanghaiInstituteforBiologicalSciences,ChineseAcademyofSciences,GraduateSchooloftheChineseAcademyofSciences,Shanghai200233,China [2]Schoolof,4gricultureandBiology,ShanghaiJiaototrgUniversity,Shanghai201101,China [3]SchoolofLifeScienceandBiotechnology,ShanghaiJiaotongUniversity,Shanghai200030,China

出　　处：《Acta Biochimica et Biophysica Sinica》2004年第8期519-528,共10页生物化学与生物物理学报（英文版）

基　　金：This work was supported by the grants from the National NaturalScience Foundation of China (No. 30070016) and the National[(High )22.5(T)63.3(echnology Research and Development Program of China)](No. 2001AA234051)

摘　　要：The hmr19 gene was cloned from Streptomyces hygroscopicus subsp. yingchengensis strain 10- 22, a bacterium strain producing agricultural antibiotics. Sequence similarity comparison indicates that hmr19 gene may encode a predicted protein with 14 putative transmembrane α-helical spanners, belonging to the drug:H+ antiporter-2 family of the major facilitator superfamily. The expression of hmr19 in the mycelium of strain 10-22 was detected by Western blotting analysis. Gene replacement technology was employed to construct an hmr19 disruption mutant. The growth inhibition test against different antibiotics indicated that the mutant strain was 5–20 fold more susceptible to tetracycline, vancomycin and mitomycin C than the parental wild type strain. The mutant took up tetracycline much faster and accumulated more antibiotics than the wild type strain 10-22. While with the addition of an energy uncoupler, carbonyl cyanide m- chlorophenylhydrazone, the characteristics of the accumulation of [3H]tetracycline in these two strains were almost the same. It was thus concluded that hmr19 encoded a multidrug resistance efflux protein.The hmr19 gene was cloned from Streptomyces hygroscopicus subsp. yingchengensis strain 10- 22, a bacterium strain producing agricultural antibiotics. Sequence similarity comparison indicates that hmr19 gene may encode a predicted protein with 14 putative transmembrane α-helical spanners, belonging to the drug:H+ antiporter-2 family of the major facilitator superfamily. The expression of hmr19 in the mycelium of strain 10-22 was detected by Western blotting analysis. Gene replacement technology was employed to construct an hmr19 disruption mutant. The growth inhibition test against different antibiotics indicated that the mutant strain was 5–20 fold more susceptible to tetracycline, vancomycin and mitomycin C than the parental wild type strain. The mutant took up tetracycline much faster and accumulated more antibiotics than the wild type strain 10-22. While with the addition of an energy uncoupler, carbonyl cyanide m- chlorophenylhydrazone, the characteristics of the accumulation of [3H]tetracycline in these two strains were almost the same. It was thus concluded that hmr19 encoded a multidrug resistance efflux protein.

关 键 词：multidrug resistance (MDR) gene replacement (knockout) STREPTOMYCES Streptomyces  hygroscopicus subsp. yingchengensis strain 10-22 

分 类 号：Q933[生物学—微生物学] Q51