Molecular basis of coiled-coil oligomerization-state specificity

Abstract

Coiled coils are extensively and successfully used nowadays to rationally design multistranded structures for applications, including basic research, biotechnology, nanotechnology, materials science, and medicine. The wide range of applications as well as the important functions these structures play in almost all biological processes highlight the need for a detailed understanding of the factors that control coiled-coil folding and oligomerization. Here, we address the important and unresolved question why the presence of particular oligomerization-state determinants within a coiled coil does frequently not correlate with its topology. We found an unexpected, general link between coiled-coil oligomerization-state specificity and trigger sequences, elements that are indispensable for coiled-coil formation. By using the archetype coiledcoil domain of the yeast transcriptional activator GCN4 as a model system, we show that well-established trimer-specific oligomerization-state determinants switch the peptide's topology from a dimer to a trimer only when inserted into the trigger sequence. We successfully confirmed our results in two other, unrelated coiled-coil dimers, ATF1 and cortexillin-1. We furthermore show that multiple topology determinants can coexist in the same trigger sequence, revealing a delicate balance of the resulting oligomerization state by position-dependent forces. Our experimental results should significantly improve the prediction of the oligomerization state of coiled coils. They therefore should have major implications for the rational design of coiled coils and consequently many applications using these popular oligomerization domains.protein folding | protein structure | protein-protein interactions

TACC3 Protein Regulates Microtubule Nucleation by Affecting γ-Tubulin Ring Complexes

“…9) implies that in addition to microtubule stabilization, TACC3 is involved in the formation of nucleation centers necessary for the initiation of microtubule polymerization. Coiled coils are unique motifs that can form extended protein structures or oligomers (55)(56)(57). Overexpressed TACC had been shown to form large oligomers in cells that were associated with microtubules (58).…”

Orange fluorescent proteins constructed from cyanobacteriochromes chromophorylated with phycoerythrobilin

“…GCN4 zipper domains form tri-or tetrameric coiled coils structure. 42 "w" denotes weak peaks. The chromophorylation yield was determined by absorption spectroscopy of the denatured purified GAFs (see Materials and methods).…”

“…For further increase of fluorescence and brightness, we employed coiled coil structures such as GCN4 leucine zipper domains which are known to oligomerize into trimers or tetramers. 42 Oligomerization of GCN4 fusion products have been reported; they form nano-complexes via the GCN4-pII or GCN4-pLI affinity tag. 19 When All2699 GAF1 was linked with GCN4-pII, the resulting GCN4::All2699 GAF1 formed hexamers (Fig.…”

Designability landscape reveals sequence features that define axial helix rotation in four-helical homo-oligomeric antiparallel coiled-coil structures

“…This observation explains how a continuum of axial rotation states in HAMP domain is reflected at the sequence level, and suggests that a similar relationship could be revealed for typical coiled coils with x-da packing. Sequence features that contribute to oligomeric and topological specificity of coiled coils have been studied extensively (Ciani et al, 2010;Ramos and Lazaridis, 2011), leading to the development of bioinformatics tools that allow prediction of these structural features directly from the sequence (Apgar et al, 2008;Vincent et al, 2013). However, sequence features that determine axial helix rotation are poorly understood.…”