Functional and structural studies of the vaccinia virus virulence factor N1 reveal a Bcl-2-like anti-apoptotic protein

1 Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK 2 The Oxford Protein Production Facility and The Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3...

Full description

Saved in:
Bibliographic Details
Published in:Journal of general virology 2007-06, Vol.88 (6), p.1656-1666
Main Authors: Cooray, Samantha, Bahar, Mohammad W, Abrescia, Nicola G. A, McVey, Colin E, Bartlett, Nathan W, Chen, Ron A.-J, Stuart, David I, Grimes, Jonathan M, Smith, Geoffrey L
Format: Article
Language:English
Subjects:
Amino Acid Sequence
Animals
bcl-2-Associated X Protein - chemistry
bcl-2-Associated X Protein - metabolism
bcl-Associated Death Protein - chemistry
bcl-Associated Death Protein - metabolism
bcl-X Protein - chemistry
BH3 Interacting Domain Death Agonist Protein - chemistry
BH3 Interacting Domain Death Agonist Protein - metabolism
Biological and medical sciences
Cell Line
Chlorocebus aethiops
Crystallography, X-Ray
Fundamental and applied biological sciences. Psychology
Humans
Immunoprecipitation
Jgv Direct
Microbiology
Miscellaneous
Models, Molecular
Molecular Sequence Data
NF-kappa B - metabolism
Protein Binding
Protein Structure, Tertiary
Vaccinia virus
Vaccinia virus - immunology
Vaccinia virus - pathogenicity
Viral Proteins - chemistry
Viral Proteins - physiology
Virology
Virulence Factors - chemistry
Virulence Factors - physiology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:1 Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK 2 The Oxford Protein Production Facility and The Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK Correspondence Geoffrey L. Smith glsmith{at}imperial.ac.uk Vaccinia virus (VACV) encodes many immunomodulatory proteins, including inhibitors of apoptosis and modulators of innate immune signalling. VACV protein N1 is an intracellular homodimer that contributes to virus virulence and was reported to inhibit nuclear factor (NF)- B signalling. However, analysis of NF- B signalling in cells infected with recombinant viruses with or without the N1L gene showed no difference in NF- B-dependent gene expression. Given that N1 promotes virus virulence, other possible functions of N1 were investigated and this revealed that N1 is an inhibitor of apoptosis in cells transfected with the N1L gene and in the context of VACV infection. In support of this finding virally expressed N1 co-precipitated with endogenous pro-apoptotic Bcl-2 proteins Bid, Bad and Bax as well as with Bad and Bax expressed by transfection. In addition, the crystal structure of N1 was solved to 2.9 Å resolution (0.29 nm). Remarkably, although N1 shows no sequence similarity to cellular proteins, its three-dimensional structure closely resembles Bcl-x L and other members of the Bcl-2 protein family. The structure also reveals that N1 has a constitutively open surface groove similar to the grooves of other anti-apoptotic Bcl-2 proteins, which bind the BH3 motifs of pro-apoptotic Bcl-2 family members. Molecular modelling of BH3 peptides into the N1 surface groove, together with analysis of their physico-chemical properties, suggests a mechanism for the specificity of peptide recognition. This study illustrates the importance of the evolutionary conservation of structure, rather than sequence, in protein function and reveals a novel anti-apoptotic protein from orthopoxviruses. Published online ahead of print on 22 March 2007 as DOI 10.1099/vir.0.82772-0. These authors contributed equally to this work. Present address: Crystallography Group, ITQB-Instituto de Tecnologia Química e Biológica, Av. República, EAN, 2784-505 Oeiras, Portugal. Present address: Department of Respiratory Medicine, Faculty of Medicine, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK. Atomic coordinates
ISSN:0022-1317
1465-2099
DOI:10.1099/vir.0.82772-0