Studies on the ADP-ribose pyrophosphatase subfamily of the Nudix hydrolases and tentative identification of trgB, a gene associated with tellurite resistance
Studies on the ADP-ribose pyrophosphatase subfamily of the Nudix hydrolases and tentative identification of trgB, a gene associated with tellurite resistance
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DOI：
10.1074/jbc.274.45.32318
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发表时间：
1999-11-05
影响因子：
4.8
通讯作者：
Bessman, MJ
中科院分区：
文献类型：
--
作者：
Dunn, CA;O'Handley, SF;Bessman, MJ
分别从酿酒酵母的ysa1、大肠杆菌的orf209、枯草芽孢杆菌的yqkg和流感嗜血杆菌的hi0398 4个Nudex水解酶基因进行扩增，克隆到表达载体上，转化大肠杆菌。对表达的蛋白进行了纯化，结果表明该蛋白属于对ADP-核糖有活性的Nudex水解酶亚家族。与其他亚家族成员的比较显示，在Nudex盒下游有一个保守的16个氨基酸残基，这是所有ADP-核糖焦磷酸酶亚家族的共同特征。在同一区域，一个保守的酪氨酸代表另一个亚家族，二腺苷多磷酸焦磷酸酶，而一系列八个保守的氨基酸代表NADH焦磷酸酶。在这些分类的基础上，从球形红杆菌中预测了一种亚碲酸盐抗性因子trgB基因，该基因被指定为ADP-核糖焦磷酸酶。为了支持这一假说，来自古细菌的高度特异的ADP-核糖焦磷酸酶基因被导入到E，Coli中，提高了转化子对亚碲酸钾的耐受性。
Four Nudix hydrolase genes, ysa1 from Saccharomyces cerevisiae, orf209 from Escherichia coli, yqkg from Bacillus subtilis, and hi0398 from Hemophilus influenzae were amplified, cloned into an expression vector, and transformed into E. coli. The expressed proteins were purified and shown to belong to a subfamily of Nudix hydrolases active on ADP-ribose. Comparison with other members of the subfamily revealed a conserved proline 16 amino acid residues downstream of the Nudix box, common to all of the ADP-ribose pyrophosphatase subfamily. In this same region, a conserved tyrosine designates another subfamily, the diadenosine polyphosphate pyrophosphatases, while an array of eight conserved amino acids is indicative of the NADH pyrophosphatases. On the basis of these classifications, the trgB gene, a tellurite resistance factor from Rhodobacter sphaeroides, was predicted to designate an ADP-ribose pyrophosphatase. In support of this hypothesis, a highly specific ADP-ribose pyrophosphatase gene from the archaebacterium, Methanococcus jannaschii, introduced into E, coli, increased the transformant's tolerance to potassium tellurite.