Tamura T, Tanaka K, Kumatori A, Yamada F, Tsurumi C, Fujiwara T, Ichihara A, Tokunaga F, Aruga R, Iwanaga S
Institute for Enzyme Research, University of Tokushima, Japan.
FEBS Lett. 1990 May 7;264(1):91-4. doi: 10.1016/0014-5793(90)80773-c.
Proteasomes are multicatalytic proteinase complexes consisting of a set of non-identical polypeptide subunits. A cDNA for component C5 of rat proteasomes was isolated by screening a Reuber H4TG hepatoma cell cDNA library using synthetic oligodeoxynucleotide probes corresponding to partial amino acid sequences of the protein. The polypeptide deduced from the open reading frame consisted of 240 amino acid residues with a calculated molecular weight of 26,479. Computer analysis revealed little similarity of C5 to other proteins reported so far. The primary structure of C5 showed partial sequence homology to that of another component C3, but no regions of homology with the sequence of component C2. Thus C5 is concluded to be a new type of subunit of the proteasome complex.
蛋白酶体是由一组不同的多肽亚基组成的多催化蛋白酶复合物。通过使用与该蛋白质部分氨基酸序列相对应的合成寡脱氧核苷酸探针筛选鲁伯H4TG肝癌细胞cDNA文库，分离出大鼠蛋白酶体组分C5的cDNA。从开放阅读框推导的多肽由240个氨基酸残基组成，计算分子量为26479。计算机分析显示C5与迄今报道的其他蛋白质几乎没有相似性。C5的一级结构与另一个组分C3的一级结构显示出部分序列同源性，但与组分C2的序列没有同源区域。因此得出结论，C5是蛋白酶体复合物的一种新型亚基。
