Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), Ministerio de Economia y Competitividad
Primary Citation of Related Structures:   5KMG
PubMed Abstract: 
Proteins that associate with microtubules (MTs) are crucial to generate MT arrays and establish different cellular architectures. One example is PRC1 (protein regulator of cytokinesis 1), which cross-links antiparallel MTs and is essential for the completion of mitosis and cytokinesis ...
Proteins that associate with microtubules (MTs) are crucial to generate MT arrays and establish different cellular architectures. One example is PRC1 (protein regulator of cytokinesis 1), which cross-links antiparallel MTs and is essential for the completion of mitosis and cytokinesis. Here we describe a 4-Å-resolution cryo-EM structure of monomeric PRC1 bound to MTs. Residues in the spectrin domain of PRC1 contacting the MT are highly conserved and interact with the same pocket recognized by kinesin. We additionally found that PRC1 promotes MT assembly even in the presence of the MT stabilizer taxol. Interestingly, the angle of the spectrin domain on the MT surface corresponds to the previously observed cross-bridge angle between MTs cross-linked by full-length, dimeric PRC1. This finding, together with molecular dynamic simulations describing the intrinsic flexibility of PRC1, suggests that the MT-spectrin domain interface determines the geometry of the MT arrays cross-linked by PRC1.
Organizational Affiliation: 
Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720; California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720; Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 enogales@lbl.gov.