Cloning, sequencing, and characterization of a gene (narT) encoding a transport protein involved in dissimilatory nitrate reduction in Staphylococcus carnosus
Cloning, sequencing, and characterization of a gene (narT) encoding a transport protein involved in dissimilatory nitrate reduction in Staphylococcus carnosus
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DOI：
10.1007/bf01682980
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发表时间：
1996-12-01
影响因子：
2.8
通讯作者：
Gotz, F
中科院分区：
文献类型：
--
作者：
Fast, B;Lindgren, PE;Gotz, F
一个Tn 917突变体的肉葡萄球菌TM 300，nrIII，分离和表征。突变体nrIII没有采取硝酸盐或积累亚硝酸盐时，生长在B-培养基中补充到10 mM的硝酸盐缺氧条件下，然而，它显示了野生型水平的苄基δ紫精连接硝酸还原酶活性，培养在B-培养基中与硝酸盐在有氧条件下，突变体nrIII积累的亚硝酸盐比野生型少五倍。S.可以用来自野生型的2-kb染色体EcoRI-HpaI片段互补肉酵母。对突变体nrIII中受转座子插入影响的基因进行克隆和测序。推导的氨基酸序列的分析表明，该基因，指定narT，编码一个高度疏水性的42-kDa的跨膜蛋白的388个氨基酸，并显示出相似的转运蛋白，发挥作用，在硝酸盐进口或亚硝酸盐出口。nrIII在缺氧条件下不能吸收硝酸盐，在相同条件下，在硝酸盐离子载体苄基紫精存在下，其吸收和积累亚硝酸盐的能力表明，NarT代表S.肉质的
A Tn917 mutant of Staphylococcus carnosus TM300, nrIII, was isolated and characterized. Mutant nrIII did not take up nitrate or accumulate nitrite when grown in B-medium supplemented with up to 10 mM nitrate under anoxic conditions; however, it displayed wild-type levels of benzyl Delta viologen-linked nitrate reductase activity, Cultivated in B-medium with nitrate under oxic conditions, mutant nrIII accumulated fivefold less nitrite than the wild-type. The mutation in S. carnosus mill could be complemented with a 2-kb chromosomal EcoRI-HpaI fragment from the wild-type. The gene affected by transposon insertion in mutant nrIII was cloned and sequenced. Analysis of the deduced amino acid sequence revealed that this gene, designated narT, encodes a highly hydrophobic 42-kDa transmembrane protein of 388 amino acids and shows similarities to transport proteins that play a role in nitrate import or nitrite export. The inability of nrIII to take up nitrate under anoxic conditions and its ability to take up and accumulate nitrite in the presence of benzyl viologen, a nitrate ionophore, under the same conditions suggest that NarT represents a transport protein required for nitrate uptake under anoxic conditions in S. carnosus.