Mehus J G, Deloukas P, Lambeth D O
Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks 58202, USA.
Hum Genet. 1999 Jun;104(6):454-9. doi: 10.1007/s004390050987.
The NME (nm23/nucleoside diphosphate kinase) gene family in human is involved in the phosphorylation of nucleoside diphosphates and a variety of regulatory phenomena associated with development, oncogenic transformation, and metastasis. Here we report the cDNA sequence for a sixth member of this family, NME6. The cDNA sequence predicts a 186-residue protein that includes the characteristic active site motif of a nucleoside diphosphate (NDP) kinase, as well as the other residues previously identified as crucial for nucleotide binding and catalysis. The NME6 protein sequence is only 34-41% identical to the five previously reported human NME proteins, and is similarly related to prokaryotic and primitive eukaryotic NDP kinases. Compared to typical proteins of this family such as NME1 and NME2, NME6 has three additional residues located in the Kpn loop, and a 22-residue extension at the COOH-terminal. Using radiation hybrid mapping, the NME6 gene was localized to chromosome 3p21.3. The 1.3-kb transcript of NME6 is expressed at a moderately low level in many human tissues, and is most abundant in kidney, prostate, ovary, intestine, and spleen. Homologous cDNAs were also cloned and sequenced for rat and mouse. The sequence of the first 171 residues of the mouse homologue (Nm23-M6) is 94% identical to the deduced human NME6 protein.
人类的NME（nm23/核苷二磷酸激酶）基因家族参与核苷二磷酸的磷酸化以及与发育、致癌转化和转移相关的多种调节现象。在此，我们报告该家族第六个成员NME6的cDNA序列。该cDNA序列预测一个由186个氨基酸残基组成的蛋白质，其包含核苷二磷酸（NDP）激酶的特征性活性位点基序，以及先前确定对核苷酸结合和催化至关重要的其他残基。NME6蛋白序列与先前报道的5种人类NME蛋白的序列同一性仅为34%-41%，并且与原核生物和原始真核生物的NDP激酶具有相似的关系。与该家族的典型蛋白如NME1和NME2相比，NME6在Kpn环中有三个额外的残基，并且在COOH末端有一个22个残基的延伸。通过辐射杂种图谱分析，NME6基因定位于染色体3p21.3。NME6的1.3kb转录本在许多人类组织中以中等低水平表达，在肾脏、前列腺、卵巢、肠道和脾脏中最为丰富。还克隆并测序了大鼠和小鼠的同源cDNA。小鼠同源物（Nm23-M6）前171个残基的序列与推导的人类NME6蛋白的序列同一性为94%。
