[1] Brown Univ, Dept Mol Biol Cell Biol & Biochem, Providence, RI 02912 USA
[2] St Laurent Inst, Cambridge, MA USA
[3] Russian Acad Sci, AP Ershov Inst Informat Syst, Siberian Branch, Novosibirsk, Russia
[4] State Res Ctr Virol & Biotechnol Vector, Novosibirsk, Russia
[5] Brown Univ, Ctr Computat Mol Biol, Dept Appl Math, Providence, RI 02912 USA