Gregg K, Wilton S D, Parry D A, Rogers G E
EMBO J. 1984 Jan;3(1):175-8. doi: 10.1002/j.1460-2075.1984.tb01779.x.
DNA sequences have been obtained for embryonic chick feather and scale keratin genes. Strong homologies exist between the protein coding regions of the two gene types and between the deduced amino acid sequences of the keratin proteins. Scale keratins are larger than feather keratins and the size difference is mainly attributable to four 13-amino acid repeats between residues 77 and 128 which compose a peptide sequence rich in glycine and tyrosine. The strong similarities between the two peptide structures for feather and scale in the homologous regions suggests a similar conformation within the protein filaments. A likely consequence is that the additional repeat region of the scale protein is located externally to the core filament. Tissue-specific features of filament aggregation may be attributable to this one striking sequence difference between the constituent proteins. It is believed that the genes share a common ancestry and that feather-like keratin genes may have evolved from a scale keratin gene by a single deletion event.
已经获得了鸡胚胎羽毛和鳞片角蛋白基因的DNA序列。这两种基因类型的蛋白质编码区之间以及角蛋白的推导氨基酸序列之间存在很强的同源性。鳞片角蛋白比羽毛角蛋白大，大小差异主要归因于77至128位残基之间的四个13氨基酸重复序列，这些重复序列组成了一个富含甘氨酸和酪氨酸的肽序列。同源区域中羽毛和鳞片的两种肽结构之间的强烈相似性表明蛋白质丝内具有相似的构象。一个可能的结果是鳞片蛋白的额外重复区域位于核心丝的外部。细丝聚集的组织特异性特征可能归因于组成蛋白之间这一显著的序列差异。人们认为这些基因有着共同的祖先，并且类似羽毛的角蛋白基因可能是通过一次缺失事件从鳞片角蛋白基因进化而来的。
