Kumar Anil, Nokhrin Sergiy, Woloschuk Ryan M, Woolley G Andrew
Department of Chemistry , University of Toronto , 80 St. George Street , Toronto , ON M5S 3H6 , Canada.
Biochemistry. 2018 Jul 17;57(28):4093-4104. doi: 10.1021/acs.biochem.8b00445. Epub 2018 Jun 28.
Duplication of a single β-strand that forms part of a β-sheet in photoactive yellow protein (PYP) was found to produce two approximately isoenergetic protein conformations, in which either the first or the second copy of the duplicated β-strand participates in the β-sheet. Whereas one conformation (big-loop) is more stable at equilibrium in the dark, the other conformation (long-tail) is populated after recovery from blue light irradiation. By appending a recognition motif (E-helix) to the C-terminus of the protein, we show that β-strand duplication, and the resulting possibility of β-strand slippage, can lead to a new switchable protein-protein interaction. We suggest that β-strand duplication may be a general means of introducing two-state switching activity into protein structures.
人们发现，在光活性黄色蛋白（PYP）中，构成β折叠一部分的单条β链发生重复，会产生两种能量大致相等的蛋白质构象，其中重复β链的第一个或第二个拷贝会参与β折叠。一种构象（大环）在黑暗中处于平衡状态时更稳定，而另一种构象（长尾）则在蓝光照射恢复后出现。通过在蛋白质的C末端附加一个识别基序（E螺旋），我们表明β链重复以及由此产生的β链滑动可能性，可导致一种新的可切换蛋白质-蛋白质相互作用。我们认为，β链重复可能是将双态切换活性引入蛋白质结构的一种普遍方式。
