skip to main content

Title: Cryo-EM structures of two bovine adenovirus type 3 intermediates

Adenoviruses (Ads) infect hosts from all vertebrate species and have been investigated as vaccine vectors. We report here near-atomic structures of two bovine Ad type 3 (BAd3) intermediates obtained by cryo-electron microscopy. A comparison between the two intermediate structures reveals that the differences are localized in the fivefold vertex region, while their facet structures are identical. The overall facet structure of BAd3 exhibits a similar structure to human Ads; however, BAd3 protein IX has a unique conformation. Mass spectrometry and cryo-electron tomography analyses indicate that one intermediate structure represents the stage during DNA encapsidation, whilst the other intermediate structure represents a later stage. These results also suggest that cleavage of precursor protein VI occurs during, rather than after, the DNA encapsidation process. Overall, our results provide insights into the mechanism of Ad assembly, and allow the first structural comparison between human and nonhuman Ads at backbone level. - Highlights: • First structure of bovine adenovirus type 3. • Some channels are located at the vertex of intermediate during DNA encapsidation. • Protein IX exhibits a unique conformation of trimeric coiled–coiled structure. • Cleavage of precursor protein VI occurs during the DNA encapsidation process.
Authors:
; ;  [1] ;  [2] ; ; ; ;  [1] ;  [3] ; ; ;  [1] ;  [2] ;  [1]
  1. National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)
  2. State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Luo-jia-shan, Wuhan, Hubei 430072 (China)
  3. College of Physics and Information Science, Hunan Normal University, Changsha, Hunan 410081 (China)
Publication Date:
OSTI Identifier:
22435015
Resource Type:
Journal Article
Resource Relation:
Journal Name: Virology; Journal Volume: 450-451; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ADENOVIRUS; COMPARATIVE EVALUATIONS; DNA; ELECTRONS; HOST; HUMAN POPULATIONS; INTERMEDIATE STRUCTURE; MASS SPECTROSCOPY; POLYPEPTIDES; PRECURSOR; TOMOGRAPHY; VACCINES