Lehrstuhl für Biochemie, Photobiochemie, Universität Bayreuth, 95447 Bayreuth, Germany; Bayreuth Center for Biochemistry & Molecular Biology, Universität Bayreuth, 95447 Bayreuth, Germany; North-Bavarian NMR Center, Universität Bayreuth, 95447 Bayreuth, Germany. Electronic address: