Xu W, Dunn C A, Bessman M J
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Biochem Biophys Res Commun. 2000 Jul 5;273(2):753-8. doi: 10.1006/bbrc.2000.2999.
Two genes from Caenorhabditis elegans and Saccharomyces cerevisiae, coding for enzymes homologous to the Nudix hydrolase family of nucleotide pyrophosphatases, have been cloned and expressed in Escherichia coli. The purified enzymes are homodimers of 39.1 and 43. 5 kDa, respectively, are activated by Mg(2+) and Mn(2+), and are 30 to 50 times more active on NADH than on NAD(+). They both have a conserved array of amino acids downstream of the Nudix box first seen in the orthologous enzyme from E. coli which designates them as members of an NADH pyrophosphatase subfamily of the Nudix hydrolases.
来自秀丽隐杆线虫和酿酒酵母的两个基因,编码与核苷酸焦磷酸酶的Nudix水解酶家族同源的酶,已被克隆并在大肠杆菌中表达。纯化后的酶分别是39.1 kDa和43.5 kDa的同型二聚体,被Mg(2+)和Mn(2+)激活,对NADH的活性比对NAD(+)高30至50倍。它们在Nudix框下游都有一个保守的氨基酸序列,这一序列最早在大肠杆菌的直系同源酶中发现,表明它们是Nudix水解酶的NADH焦磷酸酶亚家族成员。