Sun S. Y. auteur aut IRD La Scola B. auteur aut IRD Bowman V. D. auteur aut IRD Ryan C. M. auteur aut IRD Whitelegge J. P. auteur aut IRD Raoult Didier auteur aut IRD Rossmann M. G. auteur aut IRD text journalArticle eng text/pdf born digital access The virophage Sputnik is a satellite virus of the giant mimivirus and is the only satellite virus reported to date whose propagation adversely affects its host virus' production. Genome sequence analysis showed that Sputnik has genes related to viruses infecting all three domains of life. Here, we report structural studies of Sputnik, which show that it is about 740 angstrom in diameter, has a T = 27 icosahedral capsid, and has a lipid membrane inside the protein shell. Structural analyses suggest that the major capsid protein of Sputnik is likely to have a double jelly-roll fold, although sequence alignments do not show any detectable similarity with other viral double jelly-roll capsid proteins. Hence, the origin of Sputnik's capsid might have been derived from other viruses prior to its association with mimivirus. specialized 052 84 2 894-897 2010 0022-538X https://www.documentation.ird.fr/hor/fdi:010048511 10.1128/jvi.01957-09 0022-538X [F B010048511] https://www.documentation.ird.fr/hor/fdi:010048511 https://www.documentation.ird.fr/intranet/publi/2010/01/010048511.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2010-02-08 2022-04-12 fdi:010048511 fre