[1] Ben Gurion Univ Negev, Dept Comp Sci, IL-84015 Beer Sheva, Israel
[2] Univ Washington, Dept Biochem, Seattle, WA 98195 USA
[3] Univ Washington, Howard Hughes Med Inst, Seattle, WA 98195 USA
[4] Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA