4BBC

THE STRUCTURE OF VACCINIA VIRUS N1 R71Y MUTANT

Summary for 4BBC

• Entry DOI: 10.2210/pdb4bbc/pdb
• Related: 2I39 2UXE 4BBB 4BBD
• Descriptor: N1L (1 entity in total)
• Functional Keywords: viral protein, bcl-like protein, apoptosis, virulence factor
• Biological source: VACCINIA VIRUS
• Total number of polymer chains: 6
• Total formula weight: 90234.63

Authors

Maluquer de Motes, C.,Cooray, S.,McGourty, K.,Ren, H.,Bahar, M.W.,Stuart, D.I.,Grimes, J.M.,Graham, S.C.,Smith, G.L. (deposition date: 2012-09-21, release date: 2012-10-03, Last modification date: 2023-12-20)

Primary citation

Maluquer De Motes, C.,Cooray, S.,Ren, H.,Almeida, G.M.F.,Mcgourty, K.,Bahar, M.W.,Stuart, D.I.,Grimes, J.M.,Graham, S.C.,Smith, G.L.
Inhibition of Apoptosis and NF-kappaB Activation by Vaccinia Protein N1 Occur Via Distinct Binding Surfaces and Make Different Contributions to Virulence.
Plos Pathog., 7:2430-, 2011

PubMed Abstract: Vaccinia virus (VACV) protein N1 is an intracellular virulence factor and belongs to a family of VACV B-cell lymphoma (Bcl)-2-like proteins whose members inhibit apoptosis or activation of pro-inflammatory transcription factors, such as interferon (IFN) regulatory factor-3 (IRF-3) and nuclear factor-κB (NF-κB). Unusually, N1 inhibits both apoptosis and NF-κB activation. To understand how N1 exerts these different functions, we have mutated residues in the Bcl-2-like surface groove and at the interface used to form N1 homodimers. Mutagenesis of the surface groove abolished only the N1 anti-apoptotic activity and protein crystallography showed these mutants differed from wild-type N1 only at the site of mutation. Conversely, mutagenesis of the dimer interface converted N1 to a monomer and affected only inhibition of NF-κB activation. Collectively, these data show that N1 inhibits pro-inflammatory and pro-apoptotic signalling using independent surfaces of the protein. To determine the relative contribution of each activity to virus virulence, mutant N1 alleles were introduced into a VACV strain lacking N1 and the virulence of these viruses was analysed after intradermal and intranasal inoculation in mice. In both models, VACV containing a mutant N1 unable to inhibit apoptosis had similar virulence to wild-type virus, whereas VACV containing a mutant N1 impaired for NF-κB inhibition induced an attenuated infection similar to that of the N1-deleted virus. This indicates that anti-apoptotic activity of N1 does not drive virulence in these in vivo models, and highlights the importance of pro-inflammatory signalling in the immune response against viral infections.

PubMed: 22194685
DOI: 10.1371/JOURNAL.PPAT.1002430

Experimental method

X-RAY DIFFRACTION (3.1 Å)