Kefala Aikaterini, Kotsifaki Dina, Providaki Mary, Amprazi Maria, Kokkinidis Michael
Department of Biology, University of Crete, Voutes University Campus, PO Box 2208, 70013 Heraklion, Crete, Greece.
Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Nikolaou Plastira Street 100, 70013 Heraklion, Crete, Greece.
Acta Crystallogr F Struct Biol Commun. 2017 Jan 1;73(Pt 1):51-53. doi: 10.1107/S2053230X16020173.
Earlier studies have found that the occurrence of inverse sequence identity in proteins is not indicative of three-dimensional similarity, but rather leads to different folds or unfolded proteins. Short helices, however, frequently keep their conformations when their sequences are inverted. To explore the impact of sequence inversion on long helices, revRM6, with the inverse amino-acid sequence relative to RM6, a highly stable variant of the ColE1 Rop protein, was engineered. RM6 is a highly regular four-α-helical bundle that serves as a model system for protein-folding studies. Here, the crystallization and preliminary crystallographic characterization of revRM6 are reported. The protein was overexpressed in Escherichia coli, purified to homogeneity and crystallized. The crystals belonged to space group P422, with unit-cell parameters a = b = 44.98, c = 159.74 Å, and diffracted to a resolution of 3.45 Å.
早期研究发现，蛋白质中反向序列同一性的出现并不表明三维结构相似，反而会导致不同的折叠形式或未折叠的蛋白质。然而，短螺旋在其序列反转时常常保持其构象。为了探究序列反转对长螺旋的影响，构建了revRM6，其氨基酸序列相对于ColE1 Rop蛋白的高度稳定变体RM6是反向的。RM6是一个高度规则的四α螺旋束，用作蛋白质折叠研究的模型系统。在此，报道了revRM6的结晶及初步晶体学表征。该蛋白在大肠杆菌中过量表达，纯化至均一状态并进行结晶。晶体属于空间群P422，晶胞参数a = b = 44.98，c = 159.74 Å，衍射分辨率为3.45 Å。
