1 Bijvoet Center for Biomolecular Research, Science Faculty/Chemistry, Utrecht University, Utrecht, The Netherlands. Electronic address: a.m.j.j.bonvin@uu.nl.
2 Chemical and Biological Engineering, College of Engineering, and Center for Computational Biology and Bioinformatics, Koc University, 34450 Istanbul, Turkey. Electronic address: okeskin@ku.edu.tr.