1flc
From Proteopedia
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X-RAY STRUCTURE OF THE HAEMAGGLUTININ-ESTERASE-FUSION GLYCOPROTEIN OF INFLUENZA C VIRUS
Overview
The spike glycoproteins of the lipid-enveloped orthomyxoviruses and, paramyxoviruses have three functions: to recognize the receptor on the, cell surface, to mediate viral fusion with the cell membrane, and to, destroy the receptor. In influenza C virus, a single glycoprotein, the, haemagglutinin-esterase-fusion (HEF) protein, possesses all three, functions. In influenza A and B, the first two activities are mediated by, haemagglutinin and the third by a second glycoprotein, neuraminidase. Here, we report the crystal structure of the HEF envelope glycoprotein of, influenza C virus. We have identified the receptor-binding site and the, receptor-destroying enzyme (9-O-acetylesterase) sites, by using receptor, analogues. The receptor-binding domain is structurally similar to the, sialic acid-binding domain of influenza A haemagglutinin, but binds, 9-O-acetylsialic acid. The esterase domain has a structure similar to the, esterase from Streptomyces scabies and a brain acetylhydrolase. The, receptor domain is inserted into a surface loop of the esterase domain and, the esterase domain is inserted into a surface loop of the stem. The stem, domain is similar to that of influenza A haemagglutinin, except that the, triple-stranded, alpha-helical bundle diverges at both of its ends, and, the amino terminus of HEF2, the fusion peptide, is partially exposed. The, segregation of HEF's three functions into structurally distinct domains, suggests that the entire stem region, including sequences at the amino and, carboxy termini of HEF1 which precede the post-translational cleavage site, between HEF1 and HEF2, forms an independent fusion domain which is, probably derived from an ancestral membrane fusion protein.
About this Structure
1FLC is a Protein complex structure of sequences from Influenza c virus. Full crystallographic information is available from OCA.
Reference
Structure of the haemagglutinin-esterase-fusion glycoprotein of influenza C virus., Rosenthal PB, Zhang X, Formanowski F, Fitz W, Wong CH, Meier-Ewert H, Skehel JJ, Wiley DC, Nature. 1998 Nov 5;396(6706):92-6. PMID:9817207
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