英语翻译Keywords:HMG-CoA reductase,selectable marker gene,mevino

英语翻译
Keywords:HMG-CoA reductase,selectable marker gene,mevinolin,halobacteria,Archaea
INTRODUCTION
Archaea are generally resistant to most antibiotics that are active against Bacteria (Hilpert et al.,1981),and few drug resistance markers have been developed for use in genetic manipulations.In halobacteria,the three commonly used resistance determinants are novobiocin resistance (gyrB; Holmes & Dyall-Smith,1990; Holmes et al.,1994),trimethoprim resistance (Zusman et al.,1989) and mevinolin resistance (hmg; Lam & Doolittle,1989).These have been utilized in plasmid vectors,geneknockouts,transposons,gene-expression studies,etc.Mevinolin (Lovastatin,Merck) and its relatives,¯uvastatin,
pravastatin,and simvastatin,competitively inhibit HMG-CoA reductase,an enzyme found in Eucarya,Archaea and some Bacteria,and used to synthesize mevalonic acid from acetyl-CoA (see Cabrera et al.,1986; Lam & Doolittle,1989,and references therein).In humans,these drugs help lower cholesterol,but in Archaea they can completely halt growth as they block production of isoprenoid lipids (Cabrera et al.,1986),the major lipid in the cell membrane.Resistance in Haloferax volcanii arises from overproduction of the enzyme,and an up-promoter mutation in hmgA has been described and the gene used to construct the ®rst halobacterial shuttle vectors (e.g.pWL102; Lam & Doolittle,1989,1992).The mevinolin-resistance determinant,hmg,as well as the other two resistance determinants,were originally isolated from the chromosome of resistant mutants of Haloferax spp.,and since this host is recombination pro®cient,homologous recombination events are possible when vectors containing these genes are introduced nto Hfx.volcanii (e.g.Lam & Doolittle,1989; Dyall- Smith&Doolittle,1994).This can severely compromise genetic strategies that rely on selection for drug resistance.Hfx.volcanii is a preferred host for the genetic study of halobacteria,and while a recombinationde ®cient (radA) mutant of this host has been isolated,it is slow growing and is unable to maintain the replication of certain plasmids,e.g.pWL102 (Woods & Dyall- Smith,1997).In order to lower the recombination rate between the Haloferax chromosome and introduced vector plasmids,we sought a selectable marker that showed less sequence similarity to the Hfx.Volcanii genome.We report here the isolation,cloning,sequence and use in Hfx.volcanii of a mevinolin-resistance marker from Haloarcula hispanica.

主题词：HMG-CoA还原酶,可选择的标志基因,mevinolin,盐杆菌,Archaea 介绍 Archaea对是活跃的反对细菌的多数抗生素一般是有抵抗性(等Hilpert,1981),并且少量药物抵抗标志被开发了用于基因操作.在盐杆菌,三个常用的抵抗定列式是新生霉素抵抗(gyrB; holmes & Dyall史密斯1990年; Holmes等,1994),甲氧苄氨嘧啶抵抗(等Zusman,1989)和mevinolin抵抗(hmg; lam & Doolittle 1989).这些在质粒传染媒介、geneknockouts、transposons、基因表示研究等等被运用了.Mevinolin (Lovastatin,默克)和它的亲戚,¯uvastatin、 pravastatin和simvastatin,竞争地禁止HMG-CoA还原酶,发现在檀香科树木、Archaea和有些细菌和用于的酵素综合mevalonic酸从乙酰基CoA (等参见Cabrera,1986年; lam & Doolittle,在其中1989年和参考).在人,这些药物帮助更低的胆固醇,但在Archaea他们在细胞膜可以完全地制止成长,当他们阻拦isoprenoid油脂(等Cabrera的生产,1986),主要油脂.抵抗在Haloferax volcanii出现从酵素的生产过剩,并且一个促进者变化在hmgA被描述了,并且基因用于修建®rst halobacterial梭传染媒介(即.pWL102; lam & Doolittle,1989年,1992).mevinolin抵抗定列式,hmg,并且其他二个抵抗定列式,与Haloferax spp.抗性突变体染色体最初被隔绝了,并且,因为这个主人是再结合pro®cient,同源再结合事件是可能的,当包含这些基因的传染媒介是不是被介绍的Hfx时.volcanii (即.lam & Doolittle 1989年; Dyall- Smith&Doolittle 1994).这可能严厉地减弱依靠选择为药物抵抗的基因战略.Hfx.volcanii是一个首选的主人为盐杆菌的基因研究,并且,当这个主人recombinationde ®cient (radA)时突变体被隔绝了,它是生长缓慢的并且无法维护某些质粒的复制,即.pWL102 (森林& Dyall-史密斯1997).为了降低再结合率在Haloferax染色体和被介绍的传染媒介质粒之间,我们寻求显示较少序列相似性对Hfx的一个可选择的标志.Volcanii染色体.我们在Hfx报告在这儿隔离、克隆、序列和用途.mevinolin抵抗标志的volcanii从Haloarcula hispanica.