Proteopedia Entry: Coiled-Coil Structure of Keratins

The document discussed the structure and significance of type I and type II keratins, which are proteins encoded by 54 genes in the human genome. These keratins form hetero-dimers that are essential components of cytoskeletal intermediate filaments and epidermal derivatives like hair and nails. The study of keratin structure has a rich history, with the first α-helix model proposed in 1951 and the first keratin sequence determined in 1982. A model suggested by Hanukoglu and Fuchs depicted a conserved central rod with four helical domains. In 2012, Lee et al. determined the first crystal structure of a keratin helical segment, confirming the four-helix model. The Proteopedia entry provided interactive views of the keratin structure, highlighting the roles of hydrophobic and charged residues in forming coiled-coil structures. The document emphasized the educational value of incorporating keratins into biochemistry and molecular biology courses to illustrate protein structure principles and the evolution of genes.