title: The coiled-coil domain of the adenovirus type 5 protein IX is dispensable for capsid incorporation and thermostability.
abstract: The 14.4-kDa hexon-associated protein IX (pIX) acts as a cement in the capsids of primate adenoviruses and confers a thermostable phenotype. Here we show that deletion of amino acids 100 to 114 of adenovirus type 5 pIX, which eliminates the conserved coiled-coil domain, impairs its capacity to self-associate. However, pIXDelta100-114 is efficiently incorporated into the viral capsid, and the resulting virions are thermostable. Deletion of the central alanine-rich domain, as in pIXDelta60-72, does not impair self-association, incorporation into the capsid, or the thermostable phenotype. These data demonstrate, first, that the self-association of pIX is dispensable for its incorporation into the capsid and generation of the thermostability phenotype and, second, that the increased thermostability results from pIX monomers binding to different hexon capsomers rather than capsid stabilization by pIX multimers.
authors.affiliation: Department of Molecular Cell Biology, Leiden University Medical Center, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands. R.C.Hoeben@lumc.nl
authors.forename: Jort
authors.initials: J
authors.lastname: Vellinga
authors.forename: Diana J M
authors.initials: DJ
authors.lastname: van den Wollenberg
authors.forename: Stephanie
authors.initials: S
authors.lastname: van der Heijdt
authors.forename: Martijn J W E
authors.initials: MJ
authors.lastname: Rabelink
authors.forename: Rob C
authors.initials: RC
authors.lastname: Hoeben
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002213:Capsid / Q000502:physiology; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D017124:Conserved Sequence; D004279:DNA, Viral / Q000235:genetics; D017921:Mastadenovirus / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral; C018315:hexon capsid protein, Adenovirus