Fukuchi T, Nikawa J, Kimura N, Watanabe K
Department of Experimental Biology, Tokyo Metropolitan Institute of Gerontology, Japan.
Gene. 1993 Jul 15;129(1):141-6. doi: 10.1016/0378-1119(93)90710-k.
Nucleoside diphosphate kinase (NDPK) is the major enzyme responsible for the synthesis of all nucleoside triphosphates except ATP. A gene (YNK) encoding NDPK was isolated from the yeast Saccharomyces cerevisiae. The coding region consists of 459 bp encoding 153 amino acid (aa) residues. The M(r) of NDPK, calculated from the deduced aa sequence, is 17,166. Yeast NDPK was 59% and 58% identical to the rat NDPK alpha and beta, respectively. Overexpression of YNK in yeast showed high NDPK activity. The overproduced NDPK cross-reacted with anti-NDPK antibody raised against rat NDPK by Western blot analysis. Despite the fact that NDPK has features of a housekeeping enzyme, disruption of the YNK locus in a haploid strain was neither lethal nor significantly affected phenotypic behaviors such as growth rate, spore formation, mating ability and morphology. Yeast with a defective YNK still possessed NDPK activity to approximately 10% of the wild-type level. Possible sources of the remaining enzyme activity are discussed.
核苷二磷酸激酶（NDPK）是负责合成除ATP之外的所有核苷三磷酸的主要酶。从酿酒酵母中分离出一个编码NDPK的基因（YNK）。编码区由459个碱基对组成，编码153个氨基酸残基。根据推导的氨基酸序列计算，NDPK的分子量为17166。酵母NDPK与大鼠NDPKα和β分别有59%和58%的同源性。YNK在酵母中的过表达显示出高NDPK活性。通过蛋白质印迹分析，过量产生的NDPK与针对大鼠NDPK产生的抗NDPK抗体发生交叉反应。尽管NDPK具有管家酶的特征，但单倍体菌株中YNK基因座的破坏既不致死，也未显著影响诸如生长速率、孢子形成、交配能力和形态等表型行为。YNK有缺陷的酵母仍具有约为野生型水平10%的NDPK活性。文中讨论了剩余酶活性的可能来源。
