Keratins: Difference between revisions

← Older edit Newer edit →

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Israel Hanukoglu, Liora Ezra, Michal Harel, Angel Herraez

@@ Line 94: / Line 94: @@
 It can be seen that the hydrophobic residues are predominantly located in the interface between the two chains and essentially occupy the space between these chains. Thus, hydrophobic residues that can associate with one another in the aqueous environment of cell are the main points of contact between the chains in the coiled-coil.
-As the two chains of keratins are intertwined in parallel, the contact points along the entire coiled-coil represents a seam along the two proteins. Coiled-coil structures are found in many types of proteins. In two-chained coiled-coil proteins hydrophobic residues appear in a periodic pattern that has been named a heptad-repeat <ref name="Woolfson-2005">PMID:15837514</ref>. In a regular &alpha;-helix there are 3.6 residues per turn of the helix. In a left-handed coiled-coil there are 3.5 residues per turn. Thus, in a two chained coiled-coil there is a repeat pattern of seven residues that are represented by the letters a-b-c-d-e-f-g. Residues a and d in this pattern  are hydrophobic. These two residues define a hydrophobic flank for each protein. This periodic pattern was first reported on both type I and type II wool keratins <ref name="PMID697726">PMID:697726</ref> and later observed on cytoskeletal keratins as well <ref name="Hanukoglu-1983" />. The crystal structures of the 2B segment of keratins K14 and K5 provided final confirmation for the role of these hydophobic residues in coiled-coil formation <ref name="Lee-2012" />.
+As the two chains of keratins are intertwined in parallel, the contact points along the entire coiled-coil represent a seam along the two proteins. Coiled-coil structures are found in many types of proteins. In two-chained coiled-coil proteins hydrophobic residues appear in a periodic pattern that has been named a heptad-repeat <ref name="Woolfson-2005">PMID:15837514</ref>. In a regular &alpha;-helix there are 3.6 residues per turn of the helix. In a left-handed coiled-coil there are 3.5 residues per turn. Thus, in a two chained coiled-coil there is a repeat pattern of seven residues that are represented by the letters a-b-c-d-e-f-g. Residues a and d in this pattern  are hydrophobic. These two residues define a hydrophobic flank for each protein. This periodic pattern was first reported on both type I and type II wool keratins <ref name="PMID697726">PMID:697726</ref> and later observed on cytoskeletal keratins as well <ref name="Hanukoglu-1983" />. The crystal structures of the 2B segment of keratins K14 and K5 provided final confirmation for the role of these hydophobic residues in coiled-coil formation <ref name="Lee-2012" />.
 ==3D structure of keratin==