1M93

1.65 A Structure of Cleaved Viral Serpin CRMA

Summary for 1M93

• Entry DOI: 10.2210/pdb1m93/pdb
• Related: 1C8O 1F0C
• Descriptor: Serine proteinase inhibitor 2, PHOSPHATE ION, ... (5 entities in total)
• Functional Keywords: serpin, crma, apoptosis, ice inhibitor, viral protein
• Biological source: Cowpox virus; More
• Total number of polymer chains: 3
• Total formula weight: 38096.54

Authors

Simonovic, M.,Gettins, P.G.W.,Volz, K. (deposition date: 2002-07-26, release date: 2003-08-05, Last modification date: 2024-02-14)

Primary citation

Simonovic, M.,Gettins, P.G.W.,Volz, K.
Crystal structure of viral serpin crmA provides insights into its mechanism of cysteine proteinase inhibition
Protein Sci., 9:1423-1427, 2000

PubMed Abstract: 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.

PubMed: 10975564

Experimental method

X-RAY DIFFRACTION (1.65 Å)