title: Cryoelectron microscopy of protein IX-modified adenoviruses suggests a new position for the C terminus of protein IX.
abstract: Recombinant human adenovirus is a useful gene delivery vector for clinical gene therapy. Minor capsid protein IX of adenovirus has been of recent interest since multiple studies have shown that modifications can be made to its C terminus to alter viral tropism or add molecular tags and/or reporter proteins. We examined the structure of an engineered adenovirus displaying the enhanced green fluorescent protein (EGFP) fused to the C terminus of protein IX. Cryoelectron microscopy and reconstruction localized the C-terminal EGFP fusion between the H2 hexon and the H4 hexon, positioned between adjacent facets, directly above the density previously assigned as protein IIIa. The original assignment of IIIa was based largely on indirect evidence, and the data presented herein support the reassignment of the IIIa density as protein IX.
authors.affiliation: Program in Structural and Computational Biology and Molecular Biophysics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Marsh
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Campos
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Baker
authors.forename: Christopher Y
authors.initials: CY
authors.lastname: Chen
authors.forename: Wah
authors.initials: W
authors.lastname: Chiu
authors.forename: Michael A
authors.initials: MA
authors.lastname: Barry
mesh_terms: D000260:Adenoviruses, Human / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*; D002213:Capsid / Q000737:chemistry*; D020285:Cryoelectron Microscopy; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D010455:Peptides / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D014764:Viral Proteins / Q000737:chemistry
chemical_list: D010455:Peptides; D014764:Viral Proteins