PDBsum entry 1c8o

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protein Protein-protein interface(s) links
Viral protein PDB id
Protein chains
300 a.a. *
32 a.a. *
Waters ×18
* Residue conservation analysis
PDB id:
Name: Viral protein
Title: 2.9 a structure of cleaved viral serpin crma
Structure: Ice inhibitor. Chain: a. Fragment: residues 1-300. Synonym: cytokine response modifier protein. Engineered: yes. Mutation: yes. Ice inhibitor. Chain: b. Fragment: residues 301-341.
Source: Cowpox virus. Organism_taxid: 10243. Expressed in: escherichia coli. Expression_system_taxid: 562. Other_details: virus.
Biol. unit: Dimer (from PQS)
2.90Å     R-factor:   0.223     R-free:   0.287
Authors: M.Simonovic,P.G.W.Gettins,K.Volz
Key ref: M.Simonovic et al. (2000). Crystal structure of viral serpin crmA provides insights into its mechanism of cysteine proteinase inhibition. Protein Sci, 9, 1423-1427. PubMed id: 10975564 DOI: 10.1110/ps.9.8.1423
01-Jun-00     Release date:   06-Sep-00    
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Protein chain
Pfam   ArchSchema ?
P07385  (SPI2_CWPXB) -  Serine proteinase inhibitor 2
341 a.a.
300 a.a.*
Protein chain
Pfam   ArchSchema ?
P07385  (SPI2_CWPXB) -  Serine proteinase inhibitor 2
341 a.a.
32 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 8 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     extracellular space   1 term 


DOI no: 10.1110/ps.9.8.1423 Protein Sci 9:1423-1427 (2000)
PubMed id: 10975564  
Crystal structure of viral serpin crmA provides insights into its mechanism of cysteine proteinase inhibition.
M.Simonovic, Gettins PGW, K.Volz.
CrmA is an unusual viral serpin that inhibits both cysteine and serine proteinases involved in the regulation of host inflammatory and apoptosis processes. It differs from other members of the serpin superfamily by having a reactive center loop that is one residue shorter, and by its apparent inability to form SDS-stable covalent complexes with cysteine proteinases. To obtain insight into the inhibitory mechanism of crmA, we determined the crystal structure of reactive center loop-cleaved crmA to 2.9 A resolution. The structure, which is the first of a viral serpin, suggests that crmA can inhibit cysteine proteinases by a mechanism analogous to that used by other serpins against serine proteinases. However, one striking difference from other serpins, which may be significant for in vivo function, is an additional highly charged antiparallel strand for b sheet A, whose sequence and length are unique to crmA.

Literature references that cite this PDB file's key reference

  PubMed id Reference
19946139 K.Van Vliet, M.R.Mohamed, L.Zhang, N.Y.Villa, S.J.Werden, J.Liu, and G.McFadden (2009).
Poxvirus proteomics and virus-host protein interactions.
  Microbiol Mol Biol Rev, 73, 730-749.  
18729734 S.M.Best (2008).
Viral subversion of apoptotic enzymes: escape from death row.
  Annu Rev Microbiol, 62, 171-192.  
18060440 T.H.Roberts, and J.Hejgaard (2008).
Serpins in plants and green algae.
  Funct Integr Genomics, 8, 1.  
16279937 J.T.Christeller (2005).
Evolutionary mechanisms acting on proteinase inhibitor variability.
  FEBS J, 272, 5710-5722.  
15632287 L.D.Tesch, M.P.Raghavendra, T.Bedsted-Faarvang, P.G.Gettins, and S.T.Olson (2005).
Specificity and reactive loop length requirements for crmA inhibition of serine proteases.
  Protein Sci, 14, 533-542.  
12543935 B.T.Seet, J.B.Johnston, C.R.Brunetti, J.W.Barrett, H.Everett, C.Cameron, J.Sypula, S.H.Nazarian, A.Lucas, and G.McFadden (2003).
Poxviruses and immune evasion.
  Annu Rev Immunol, 21, 377-423.  
12160859 H.Everett, and G.McFadden (2002).
Poxviruses and apoptosis: a time to die.
  Curr Opin Microbiol, 5, 395-402.  
11852247 H.R.Stennicke, C.A.Ryan, and G.S.Salvesen (2002).
Reprieval from execution: the molecular basis of caspase inhibition.
  Trends Biochem Sci, 27, 94.  
11939796 J.A.Irving, R.N.Pike, W.Dai, D.Brömme, D.M.Worrall, G.A.Silverman, T.H.Coetzer, C.Dennison, S.P.Bottomley, and J.C.Whisstock (2002).
Evidence that serpin architecture intrinsically supports papain-like cysteine protease inhibition: engineering alpha(1)-antitrypsin to inhibit cathepsin proteases.
  Biochemistry, 41, 4998-5004.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.