3s4r
From Proteopedia
Crystal structure of vimentin coil1A/1B fragment with a stabilizing mutation
Structural highlights
Function[VIME_HUMAN] Vimentins are class-III intermediate filaments found in various non-epithelial cells, especially mesenchymal cells. Vimentin is attached to the nucleus, endoplasmic reticulum, and mitochondria, either laterally or terminally.[1] Involved with LARP6 in the stabilization of type I collagen mRNAs for CO1A1 and CO1A2.[2] Publication Abstract from PubMedTogether with actin filaments and microtubules, intermediate filaments (IFs) are the basic cytoskeletal components of metazoan cells. Over 80 human diseases have been linked to mutations in various IF proteins to date. However, the filament structure is far from being resolved at the atomic level, which hampers rational understanding of IF pathologies. The elementary building block of all IF proteins is a dimer consisting of an alpha-helical coiled-coil (CC) "rod" domain flanked by the flexible head and tail domains. Here we present three crystal structures of overlapping human vimentin fragments that comprise the first half of its rod domain. Given the previously solved fragments, a nearly complete atomic structure of the vimentin rod has become available. It consists of three alpha-helical segments (coils 1A, 1B, and 2) interconnected by linkers (L1 and L12). Most of the CC structure has a left-handed twist with heptad repeats, but both coil 1B and coil 2 also exhibit untwisted, parallel stretches with hendecad repeats. In the crystal structure, linker L1 was found to be alpha-helical without being involved in the CC formation. The available data allow us to construct an atomic model of the antiparallel tetramer representing the second level of vimentin assembly. Although the presence of the nonhelical head domains is essential for proper tetramer stabilization, the precise alignment of the dimers forming the tetramer appears to depend on the complementarity of their surface charge distribution patterns, while the structural plasticity of linker L1 and coil 1A plays a role in the subsequent IF assembly process. Atomic structure of the vimentin central alpha-helical domain and its implications for intermediate filament assembly.,Chernyatina AA, Nicolet S, Aebi U, Herrmann H, Strelkov SV Proc Natl Acad Sci U S A. 2012 Aug 21;109(34):13620-5. doi:, 10.1073/pnas.1206836109. Epub 2012 Aug 6. PMID:22869704[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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