操纵子的vacuolar-type Na(+)腺苷三磷酸酶hirae肠球菌。
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Solioz M,戴维斯K
操纵子的vacuolar-type Na(+)腺苷三磷酸酶hirae肠球菌。
J生物化学杂志。1994年4月1;269 (13):9453 - 9。
- PubMed ID
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8144530 (在PubMed]
- 文摘
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革兰氏阳性细菌肠球菌hirae驱逐钠由两个系统:一个Na + / H(+)逆向转运和vacuolar-type Na(+)腺苷三磷酸酶。我们孤立的突变,NalkA Na (+) atp酶的缺陷。NalkA增长通常在中性pH值但无法生长在> 100 mM的存在钠在pH值9.5。通过功能互补高pH值,我们克隆pES1,质粒的大肠hirae基因库包含5.2千碱基配对地区的基因组DNA。pES1中的基因组DNA包含五个完整的开放阅读框架,ntpM, n, o, - p, q,编码蛋白质,75年16日,23日,38岁和11 kDa。六分之一不完整的开放阅读框,国家结核控制规划的L,先于ntpM。克隆的DNA的3 '端与先前发表的序列编码ntpA和ntpB子单元的大肠hirae Na(+)腺苷三磷酸酶(Takase, K。日本人,我。,Kakinuma y 1993)生物。268年化学,11610 - 11616)。的插入pES1因此代表了国家结核控制规划操纵子的上游地区编码大肠hirae Na(+)腺苷三磷酸酶。 Complementation analysis with various deletions derived from pES1 suggest that the original mutation is in the ntpM gene. Of the new genes described here, three exhibited significant sequence similarity to known proteins; ntpM shares 24% identical amino acid residues with the "116-kDa" subunits of eukaryotic vacuolar ATPases, ntpN exhibits 28% sequence identity with the 16-kDa proteolipid of human vacuolar ATPase, and ntpO has sequence homology to the 31-kDa subunit of the bovine kidney vacuolar ATPase. No known proteins with sequence similarity to ntp'L, -P, or -Q could be identified. Disruption of either ntpM, -N, or -O in wild-type cells by cassette mutagenesis resulted in mutants unable to effect ATP-driven sodium extrusion. NtpM, -N, and -O therefore represent three new gene products involved in sodium extrusion by the vacuolar-type Na(+)-ATPase of E. hirae, and three more gene products, NtpL, -P, and -Q, may also be constituents of this enzyme. The ntp operon thus contains at least eight genes.