[1] Ecole Normale Super Lyon, Labretro INSERM 758, IFR Biosci 128, F-69364 Lyon 07, France
[2] Univ Amsterdam, Acad Med Ctr, CINIMA,Lab Expt Viriol, Dept Med Microbiol, NL-1105 AZ Amsterdam, Netherlands
[3] Inc NCI Frederick, AIDS Vaccine Program SAIC, Ft Detrick, MD 21702 USA
[4] Univ Maryland Baltimore Cty, Dept Chem & Biochem, Baltimore, MD 21250 USA
[5] Univ Maryland Baltimore Cty, Howard Hughes Med Inst, Baltimore, MD 21250 USA
[6] Univ Strasbourg 1, CNRS, Inst Gilbert Laustrait,UMR 7175, Dept Pharmacol & Physico Chem, F-67401 Illkirch Graffenstaden, France