1. Center for Advanced Research in Biotechnology, National Institute of Standards and Technology and the University of Maryland Biotechnology Institute, 9600 Gudelsky Drive, Rockville, Maryland 20850, The Laboratory of Light Sensitive Systems, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia, and the Institute of Biological Physics, Russian Academy of Sciences, Pushchino, Moscow Region, Russia