Keratins: Difference between revisions
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The first model of alpha-helix was proposed by Pauling based on the crystallography of wool fibers <ref>PMID:12966187</ref> that were shown to have long helical segments <ref>PMID:6072928</ref>. | The first model of alpha-helix was proposed by Pauling based on the crystallography of wool fibers <ref>PMID:12966187</ref> that were shown to have long helical segments <ref>PMID:6072928</ref>. | ||
Analysis of the first cytoskeletal keratin sequence revealed that this protein contains a central domain of ~310 residues that was predicted to be mostly in α-helix conformation <ref name="PMID6186381" />. By comparative analysis of the predicted structures of a type I keratin, a type II keratin, desmin and vimentin, Hanukoglu and Fuchs suggested that all IF proteins have a central ~ | Analysis of the first cytoskeletal keratin sequence revealed that this protein contains a central domain of ~310 residues that was predicted to be mostly in α-helix conformation <ref name="PMID6186381" />. By comparative analysis of the predicted structures of a type I keratin, a type II keratin, desmin and vimentin, Hanukoglu and Fuchs suggested that all IF proteins have a central ~310 residue domain that contains four segments in α-helical conformation that are separated by three short linker segments predicted to be in beta-turn conformation <ref name="PMID6191871" />. This model has been confirmed by analysis of the crystal structure of segments of keratin coiled-coil <ref name="PMID22705788" >PMID:22705788</ref>. | ||
The structures of the head and tail domains of keratins are highly variable and have not been elucidated. Based on their sequences, these domains are predicted to be non-helical, probably forming globular structures that participate in interactions between subunits and other proteins in the scaffold of cellular cytoskeleton <ref name="PMID19422428" />. | The structures of the head and tail domains of keratins are highly variable and have not been elucidated. Based on their sequences, these domains are predicted to be non-helical, probably forming globular structures that participate in interactions between subunits and other proteins in the scaffold of cellular cytoskeleton <ref name="PMID19422428" />. | ||