[1] HARVARD UNIV, SCH MED, DEPT MICROBIOL & MOLEC GENET, BOSTON, MA 02115 USA
[2] KYOTO UNIV, INST VIRUS RES, KYOTO 606, JAPAN
[3] TUFTS UNIV, SCH MED, DEPT PHYSIOL, BOSTON, MA 02111 USA
[4] UNIV TOKYO, INST APPL MICROBIOL, TOKYO 113, JAPAN
[5] SUNY STONY BROOK, DEPT MICROBIOL, STONY BROOK, NY 11794 USA
[6] WASHINGTON STATE UNIV, BIOCHEM BIOPHYS PROGRAM, PULLMAN, WA 99164 USA
[7] PRINCETON UNIV, DEPT MOLEC BIOL, PRINCETON, NJ 08544 USA
[8] BOSTON BIOMED RES INST, DEPT METAB REGULAT, BOSTON, MA 02114 USA
[9] UNIV CALIF LOS ANGELES, SCH MED, INST MOLEC BIOL, LOS ANGELES, CA 90024 USA