This Article Full Text (PDF) Other Versions of this Article: JVI.01732-07v1 81/23/12785    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, H. Articles by Lieber, A. Search for Related Content PubMed PubMed Citation Articles by Wang, H. Articles by Lieber, A.

 Previous Article  |  Next Article 

J. Virol. doi:10.1128/JVI.01732-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Identification of CD46 binding sites within the adenovirus serotype 35 fiber knob

Division of Medical Genetics, Department of Medicine, Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan; Interfaculty Institute for Biochemistry, University of Tübingen, D-72076 Tübingen, Germany; Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan

^* To whom correspondence should be addressed. Email: lieber00{at}u.washington.edu.

	Abstract

Species B human adenoviruses (Ads) are often associated with fatal illnesses in immunocompromised individuals. Recently, species B Ads, most of which use the ubiquitously expressed complement regulatory protein CD46 as a primary attachment receptor, have gained interest for use as gene therapy vectors. In this study, we focused on species B serotype Ad35, whose trimeric fiber knob domain binds to three CD46 molecules with a K_D of 15.5 nM. To study the Ad35 knob-CD46 interaction, we generated an expression library of Ad35 knobs with random mutations, and screened it for CD46 binding. We identified four critical residues (Phe242, Arg279, Ser282, Glu302) which, when mutated, ablated Ad35 knob binding to CD46, without affecting knob trimerization. The functional importance of the identified residues was validated in surface plasmon resonance (SPR) and competition binding studies. To model Ad35 knob-CD46 interaction, we resolved the Ad35 knob structure at 2Å resolution by x-ray crystallography and overlaid it onto the existing structure for Ad serotype 11 - CD46 interaction. According to our model, all identified Ad35 residues are in regions that interact with CD46, whereby one CD46 molecule binds between two knob monomers. This mode of interaction might have potential consequences for CD46 signaling and intracellular trafficking of Ad35. Our findings are also fundamental for better characterization of species B Ads, design of antiviral drugs, as well as for application of species B Ads as in vivo and in vitro gene transfer vectors.

This article has been cited by other articles:

• Pache, L., Venkataraman, S., Reddy, V. S., Nemerow, G. R. (2008). Structural Variations in Species B Adenovirus Fibers Impact CD46 Association. J. Virol. 82: 7923-7931 [Abstract] [Full Text]