Protein coiled coils

Detailed structure determinations of GCN4 and other coiled-coil proteins have shown that the a helices pack against each other according to the "knobs in holes" model first suggested by Francis Crick (Figure 3.5). Each side chain in the hydrophobic region of one of the a helices can contact four side chains from the second a helix. The side chain of a residue in position "d"... 

Amino acid substitutions on the native y52 8sKIpeptide, coiled-coil domain of human fibrin were able to stabilize the coiled-coil formation. These substitutions were targeted to the positions that compose the interface between coiled-coil strands while the solvent-exposed residues were left unperturbed. This strategy aimed at reducing the likelihood of immunogenicity for future in vivo apphcafion of these materials. In contrast to PEG block copolymers with end blocks that are not used for directed assembly, PEG copolymers with coiled-coil protein motives aim to enhance intermolecular interactions and control over the assembly conditions [85, 173]. 

Fong JH, Keating AE, Singh M (2004) Predicting specificity in bZIP coiled-coil protein interactions. Genome Biol 5 R11... 

WangC, Stewart RJ, Kopecek J (1999) Hybrid hydrogels assembled from synthetic polymers and coiled-coil protein domains. Nature 397 417-420... 

Keratins are made of filaments, approximately 10 nm in diameter and hundreds of nanometers in length, via assembly of rod-shaped, coiled-coil proteins. Filament formation is initiated by the creation of a dimer comprising monomeric units 44-54 nm in length. Such dimers may form three types of lateral interactions leading to filament formation from equimolar amounts of acidic and basic dimers. In vitro assembly involves the correct alignment of two, three, or four dimers into a nucleus for further, rapid filament assembly [6]. 

Akhmedov AT, Gross B, Jessberger R 1999 Mammalian SMC3 C-terminal and coiled-coil protein domains specifically bind palindromic DNA, do not block DNA ends, and prevent DNA bending. J Biol Chem 274 38216-38224... 

Hirano T, Mitchison TJ 1994 A heterodimeric coiled-coil protein required for mitotic chromosome condensation in vitro. Cell 79 449-458... 

Barr, F. (1999). A novel rab6-interacting domain defines a family of Golgi-targeted coiled-coil proteins. Gurr. Biol. 9, 381-384. 

Munro, S., and Nichols, B. (1999). The grip domain—a novel Golgi-targeting domain found in several coiled-coil proteins. Gun. Biol. 9, 377—380. 

Figure 3 Schematic illustration of a hybrid hydrogel system—genetically engineered coiled-coil protein domains used to crosslink synthetic water-soluble polymers. Divalent transition metal ions are shown to form complexes with nitrogen-oxygen-donor ligands on the synthetic polymer side chains and the terminal histidine residues in the coiled coils.

TABLE 1. Characterization of the Coiled-Coil Protein Crosslinkers. 

A. Rose, I. Meier, Scaffolds, levers, rods and springs Diverse cellular functions of long coiled-coil proteins. Cell. Mol. Life Sci. 61(16) (2004) 1996-2009. 

Y. Tang, G. Ghirlanda, W.A. Petka, T. Nakajima, W.F. DeGrado, D.A. Tirrell, Fluorinated coiled coil proteins prepared in vivo display enhanced thermal and chemical stability, Angew. Chem. Int. Ed. 40(8) (2001) 1494-1496. 

Y. Tang, D.A. Tirrell, Biosynthesis of a highly stable coiled coil protein containing hexafluoroleucine in an engineered bacterial host, J. Am. Chem. Soc. 123(44) (2001) 11089-11090. 

Marshall, J., and Holberton, D. V. (1993). Sequence and structure of a new coiled-coil protein from a microtubule bundle in Giardia. J. Mol. Biol. 231, 521-530. 

Fig. 1. Gallery of canonical, heptad-based coiled-coil proteins. Coiled-coil segments are shown in red, other a-helices in yellow, and /3-strands in green.

Seo, J., and Cohen, C. (1993). Pitch diversity in a-helical coiled coils. Proteins 15, 223-234. Erratum in Proteins 17, 219. 

Wolf, E., Kim, P. S., and Berger, B. (1997). MultiCoil A program for predicting two-and three-stranded coiled coils. Protein Science 6, 1179-1189. 

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