Structure and topology of the linkers in the conserved lepidosaur β-keratin chain with four 34-residue repeats support an interfilament role for the central linker

Ashton, 2013, Self-tensioning aquatic caddisfly silk: Ca2+-dependent structure, strength, and liquid cycle hysteresis, Biomacromology, 14, 3668, 10.1021/bm401036z Bear, 1951, The results of X-ray diffraction studies on keratin fibers, Ann. N.Y. Acad. Sci., 53, 627, 10.1111/j.1749-6632.1951.tb31964.x Bittencourt, 2007, Spidroins from the Brazilian spider Nephilengys cruentata (Aranae: Nephilidae), Comp. Biochem. Physiol. Part B, 147, 597, 10.1016/j.cbpb.2007.03.013 Calvaresi, 2016, The molecular organization of the beta-sheet region in corneous beta-proteins (beta-keratins) of sauropsids explains it stability and polymerization into filaments, J. Struct. Biol., 194, 282, 10.1016/j.jsb.2016.03.004 Dalla Valle, 2010, Forty keratin-associated β-proteins (β-proteins) form the hard layers of scales, claws, adhesive pads in the green anole lizard, Anolis carolinensis, J. Exp. Zool., 314B, 11, 10.1002/jez.b.21306 Dicko, 2004, Structural conformation of spidroin in solution: A synchrotron radiation circular dichroism study, Biomacromolecules, 5, 758, 10.1021/bm034373e Dicko, 2006, β-silks: Enhancing and controlling aggregation, Adv. Prot. Chem., 73, 17 Drozdetskiy, 2015, JPred4: a protein secondary structure prediction server, Nucleic Acids Res., 43, W389, 10.1093/nar/gkv332 Filshie, 1964, X-ray diffraction and electron microscope observations on soluble derivatives of feather keratin, Biochem. J., 92, 18, 10.1042/bj0920018 Fraser, 1963, Structural organization in feather keratin, J. Mol. Biol., 7, 272, 10.1016/S0022-2836(63)80007-8 Fraser, 1973 Fraser, 1976, The molecular structure of feather keratin, 443 Fraser, 2008, Molecular packing in the feather keratin filament, J. Struct. Biol., 162, 1, 10.1016/j.jsb.2008.01.011 Fraser, 2011, The structural basis of the filament-matrix texture in the avian/reptilian group of hard β-keratins, J. Struct. Biol., 173, 391, 10.1016/j.jsb.2010.09.020 Fraser, 2011, The structural basis of the two-dimensional net pattern observed in the X-ray diffraction pattern of avian keratin, J. Struct. Biol., 176, 340, 10.1016/j.jsb.2011.08.010 Fraser, 2014, Amino acid sequence homologies in the hard keratins of birds and reptiles, and their implications for molecular structure and physical properties, J. Struct. Biol., 188, 213, 10.1016/j.jsb.2014.10.012 Fraser, 2017, Filamentous structure of hard β-keratin in the epidermal appendages of birds and reptiles, 231 Fraser, 2020, Lepidosaur β-keratin chains with four 34-residue repeats: Modelling reveals a potential filament-crosslinking role, J. Struct. Biol., 209, 10.1016/j.jsb.2019.107413 Fraser, 1965, Polypeptide chain conformation in feather keratin, J. Mol. Biol., 14, 279, 10.1016/S0022-2836(65)80247-9 Fraser, 1965, Poly-L-alanylglycine, J. Mol. Biol., 11, 706, 10.1016/S0022-2836(65)80028-6 Fraser, 1966, Poly–L-alanylglycyl-L-alanylglycyl- L-serylglycine: A model for the crystalline regions of silk fibroins, J. Mol. Biol., 19, 580, 10.1016/S0022-2836(66)80026-8 Fraser, 1971, The structure of feather keratin, Polymer, 12, 35, 10.1016/0032-3861(71)90011-5 Holthaus, 2017, Identification and comparative analysis of the epidermal differentiation complex in snakes, Sci. Rep., 7, 45338, 10.1038/srep45338 Jones, 1999, Protein secondary structure prediction based on position-specific scoring matrices, J. Mol. Biol., 292, 195, 10.1006/jmbi.1999.3091 Liu, 2015, Gekko japonicus genome reveals evolution of adhesive toe pads and tail regeneration, Nature Commun., 6, 10033, 10.1038/ncomms10033 O’Donnell, 1973, The complete amino acid sequence of a feather keratin from emu (Dromaius novae-hollandiae), Aust. J. Biol. Sci., 26, 415, 10.1071/BI9730415 Parry, 2005, Structural and functional implications of sequence repeats in fibrous proteins, Adv. Proc. Chem., 70, 11 Parry, 2008, Fifty years of coiled-coils and α-helical bundles: a close relationship between sequence and structure, J. Struct. Biol., 163, 258, 10.1016/j.jsb.2008.01.016 Parry, 2019, Molecular structure of sauropsid β-keratins from tuatara (Sphenodon punctatus), J. Struct. Biol., 207, 21, 10.1016/j.jsb.2019.04.008 Rice, 2013, Chicken corneocyte cross-linked proteome, J. Proteome Res., 12, 771, 10.1021/pr301036k Römer, 2008, The elaborate structure of spider silk: Structure and function of a natural high performance fiber, Prion, 2, 154, 10.4161/pri.2.4.7490 Strasser, 2015, Convergent evolution of cysteine-rich proteins in feathers and hair, BMC Evol. Biol., 15, 82, 10.1186/s12862-015-0360-y Warwicker, 1954, The crystal structure of silk fibroin, Acta Cryst., 7, 565, 10.1107/S0365110X54001867 Wu, 2015, Topographical mapping of α- and β-keratins on developing chicken skin integument: functional interaction and evolutionary perspectives, Proc. Natl. Acad. Sci. U.S.A, 122, E6770, 10.1073/pnas.1520566112