New data on the microtubule surface lattice
作者:
Denis Chrétien,
Richard H. Wade,
期刊:
Biology of the Cell
(WILEY Available online 1991)
卷期:
Volume 71,
issue 1‐2
页码: 161-174
ISSN:0248-4900
年代: 1991
DOI:10.1016/0248-4900(91)90062-R
出版商: Blackwell Publishing Ltd
关键词: microtubules;cryo‐electron microscopy;microtubule structure;microtubule polymorphism
数据来源: WILEY
摘要:
Summary—Thein vitropolymerisation of tubulin is a remarkable example of protein self‐assembly in thet several closely related microtubule structures coexist on the polymerisation plateau. Unfixed and unstainedin vitroassembled microtubules were observed in vitreous ice by cryo‐electron microscopy. New results are reported that considerably extend previous observations [47]. In ice, microtubule images have a distinctive contrast related to the number and skew of the photofilaments. The microtubules observed have from twelve to seventeen protofilaments. Comparison with thin sections of pelleted material allows a direct identification of images from microtubules with thirteen, fourteen and fifteen protofilaments. A surface lattice accommodation mechanism, previously proposed to explain how variable numbers of protofilaments can be incorporated into the basic thirteen protofilament structure, is described in detail. Our new experimental results are shown to be in overall agreement with the theoretical predictions. Only thirteen protofilament microtubules have unskewed protofilaments, this was confirmed by observations on axoneme fragments. The results imply that the microtubule surface lattice is based on a mixed packing which combines features of the standard A and B lat
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