Affolter M, Hemphill A, Roditi I, Müller N, Seebeck T
Institut für allgemeine Mikrobiologie, University of Bern, Switzerland.
J Struct Biol. 1994 May-Jun;112(3):241-51. doi: 10.1006/jsbi.1994.1024.
The microtubular membrane skeleton of Trypanosoma brucei contains two closely related, repetitive, high-molecular-weight microtubule-associated proteins, MARP-1 and MARP-2 (MARP for Microtubule-Associated Repetitive Proteins). Their structure is unusual in that they consist of tandemly arranged, strongly conserved 38-amino-acid repeat units over almost their entire length of about 320 kDa. Their nonrepetitive N and C ends are comparatively short. The predicted amino acid sequences reveal a gradient of similarity between MARP-1 and MARP-2 which increases from the N-terminus (no significant similarity) through the repeat domain (50% similarity) to the C-terminus (94.5% similarity). Transfection of mammalian cell lines with recombinant fragments of MARP-2 demonstrate that the nonrepetitive C-terminus of MARP-2 binds specifically to microtubules. This C-terminus does not show sequence similarity with any other microtubule-associated proteins and thus appears to represent a novel type of microtubule-binding domain.
布氏锥虫的微管膜骨架包含两种密切相关、重复的高分子量微管相关蛋白，MARP-1和MARP-2（MARP即微管相关重复蛋白）。它们的结构不同寻常，几乎在其约320 kDa的整个长度上都由串联排列、高度保守的38个氨基酸重复单元组成。它们的非重复N端和C端相对较短。预测的氨基酸序列显示MARP-1和MARP-2之间的相似性梯度从N端（无显著相似性）通过重复结构域（50%相似性）到C端（94.5%相似性）逐渐增加。用MARP-2的重组片段转染哺乳动物细胞系表明，MARP-2的非重复C端特异性结合微管。这个C端与任何其他微管相关蛋白都没有序列相似性，因此似乎代表了一种新型的微管结合结构域。
