Wothe D D, Charbonneau H, Shapiro B M
Department of Biochemistry, University of Washington, Seattle 98195.
Proc Natl Acad Sci U S A. 1990 Jul;87(13):5203-7. doi: 10.1073/pnas.87.13.5203.
TCK, the creatine kinase (ATP:creatine N-phosphotransferase) from sperm flagella of the sea urchin Strongylocentrotus purpuratus, is a Mr 145,000 axonemal protein that is employed in energy transport. Its amino acid sequence was obtained by analysis of fragments from cyanogen bromide digestion and by sequencing cDNA clones from two sea urchin testis libraries. TCK contains three complete but nonidentical creatine kinase segments joined by regions of sequence that are not creatine kinase-like and flanked by unique amino and carboxyl termini. Each creatine kinase segment is homologous to vertebrate creatine kinases of both muscle and brain types, and all three repeats contain the essential active-site cysteine. The sequence differences among repeats suggest an ancient gene triplication, around the time of the chordate-echinoderm divergence. The echinoderm, with a unique creatine kinase in sperm, arginine kinase in eggs, and both phosphagen kinases in somatic cells, may represent a preserved branch point in evolution, and TCK may be a relic of this event.
紫球海胆精子鞭毛中的肌酸激酶（ATP：肌酸N-磷酸转移酶）TCK是一种分子量为145,000的轴丝蛋白，用于能量运输。通过对溴化氰消化片段的分析以及对两个海胆睾丸文库中的cDNA克隆进行测序，获得了其氨基酸序列。TCK包含三个完整但不相同的肌酸激酶片段，这些片段由非肌酸激酶样的序列区域连接，并由独特的氨基和羧基末端侧翼。每个肌酸激酶片段与肌肉和脑型脊椎动物肌酸激酶同源，并且所有三个重复序列都包含必需的活性位点半胱氨酸。重复序列之间的序列差异表明，在脊索动物-棘皮动物分化时期左右发生了一次古老的基因三倍化。棘皮动物在精子中具有独特的肌酸激酶，在卵子中具有精氨酸激酶，在体细胞中具有两种磷酸原激酶，可能代表了进化中一个保留的分支点，而TCK可能是这一事件的遗迹。
