Nucleoside Diphosphate Linked Moiety X-Type Motif 8 (NUDT8)

A mouse homologue of the Saccharomyces cerevisiae Pcd1p coenzyme A diphosphatase, NUDT7alpha, has been expressed as a thioredoxin fusion protein in Escherichia coli. In most cases, higher organisms possess two related sequences, e.g. mouse Nudt7 and Nudt8, one of which encodes a peroxisomal enzyme (e.g. Nudt7).NUDT7alpha is also a CoA diphosphatase of the nudix hydrolase family, and hydrolyses CoA, CoA esters and oxidized CoA with similar efficiences, yielding 3""",5"""-ADP and the corresponding 4"""-phosphopantetheine derivative as products. K(m) and k(cat) values with CoA were 240 microM and 3.8 s(-1). Activity was optimal at pH 8.0 with 5 mM Mg(2+) or Mn(2+) ions, while fluoride was inhibitory with an IC(50) value of 20 microM.