Richardson Jane S, Videau Lizbeth L, Williams Christopher J, Richardson David C
Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA.
Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA.
J Mol Biol. 2017 May 5;429(9):1321-1335. doi: 10.1016/j.jmb.2017.03.017. Epub 2017 Mar 20.
Vicinal disulfides between sequence-adjacent cysteine residues are very rare and rather startling structural features which play a variety of functional roles. Typically discussed as an isolated curiosity, they have never received a general treatment covering both cis and trans forms. Enabled by the growing database of high-resolution structures, required deposition of diffraction data, and improved methods for discriminating reliable from dubious cases, we identify and describe distinct protein families with reliably genuine examples of cis or trans vicinal disulfides and discuss their conformations, conservation, and functions. No cis-trans interconversions and only one case of catalytic redox function are seen. Some vicinal disulfides are essential to large, functionally coupled motions, whereas most form the centers of tightly packed internal regions. Their most widespread biological role is providing a rigid hydrophobic contact surface under the undecorated side of a sugar or multiring ligand, contributing an important aspect of binding specificity.
序列相邻的半胱氨酸残基之间的邻位二硫键非常罕见，是相当惊人的结构特征，发挥着多种功能作用。通常作为一个孤立的奇闻轶事来讨论，它们从未得到过涵盖顺式和反式形式的全面论述。随着高分辨率结构数据库的不断增加、衍射数据的要求存档以及区分可靠与可疑情况的改进方法，我们识别并描述了具有可靠的顺式或反式邻位二硫键真实例子的不同蛋白质家族，并讨论了它们的构象、保守性和功能。未观察到顺反互变，仅发现一例催化氧化还原功能。一些邻位二硫键对于大规模的功能偶联运动至关重要，而大多数形成紧密堆积的内部区域的中心。它们最广泛的生物学作用是在糖或多环配体未修饰的一侧提供一个刚性的疏水接触表面，这是结合特异性的一个重要方面。
