Journal of Structural Biology ( IF 3 ) Pub Date : 2021-09-03 , DOI: 10.1016/j.jsb.2021.107793 David A D Parry 1 , David J Winter 1
On the basis of sequence homology with mammalian α-keratins, and on the criteria that the coiled-coil segments and central linker in the rod domain of these molecules must have conserved lengths if they are to assemble into viable intermediate filaments, a total of 28 Type I and Type II keratin intermediate filament chains (KIF) have been identified from the genome of the European common wall lizard (Podarcis muralis). Using the same criteria this number may be compared to 33 found here in the green anole lizard (Anole carolinensis) and 25 in the tuatara (Sphenodon punctatus). The Type I and Type II KIF genes in the wall lizard fall in clusters on chromosomes 13 and 2 respectively. Although some differences occur in the terminal domains in the KIF chains of the two lizards and tuatara, the similarities between key indicator residues – cysteine, glycine and proline – are significant. The terminal domains of the KIF chains in the wall lizard also contain sequence repeats commonly based on glycine and large apolar residues and would permit the fine tuning of physical properties when incorporated within the intermediate filaments. The H1 domain in the Type II chain is conserved across the lizards, tuatara and mammals, and has been related to its role in assembly at the 2–4 molecule level. A KIF-like chain (K80) with an extensive tail domain comprised of multiple tandem repeats has been identified as having a potential filament-crosslinking role.
中文翻译:
欧洲常见壁蜥(Podarcis Muralis)中的角蛋白中间丝链和潜在的角蛋白丝交联剂
根据与哺乳动物 α-角蛋白的序列同源性,以及这些分子的棒状结构域中的卷曲螺旋片段和中心接头如果要组装成可行的中间丝必须具有保守长度的标准,总共 28 I 型和 II 型角蛋白中间丝链 (KIF) 已从欧洲普通壁蜥 ( Podarcis wallis ) 的基因组中鉴定出来。使用相同的标准,这个数字可以与在绿色蜥蜴 ( Anole carolinensis ) 中发现的 33 和在大蜥蜴 ( Sphenodon punctatus ) 中发现的 25 进行比较)。壁蜥中的 I 型和 II 型 KIF 基因分别聚集在 13 号和 2 号染色体上。尽管两种蜥蜴和大蜥蜴的 KIF 链的末端结构域存在一些差异,但关键指示剂残基——半胱氨酸、甘氨酸和脯氨酸——之间的相似性是显着的。壁蜥中 KIF 链的末端结构域还包含通常基于甘氨酸和大的非极性残基的序列重复,并且当掺入中间细丝时将允许对物理性质进行微调。II 型链中的 H1 结构域在蜥蜴、大蜥蜴和哺乳动物中是保守的,并且与其在 2-4 分子水平上的组装作用有关。