4nkj

From Proteopedia

Structure of influenza B virus hemagglutinin at membrane fusion pH

Structural highlights

4nkj is a 1 chain structure with sequence from Influenza B virus (B/Texas/3394/2013). Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.4535Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

S5DRP1_9INFB Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. This attachment induces virion internalization of about two third of the virus particles through clathrin-dependent endocytosis and about one third through a clathrin- and caveolin-independent pathway. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore (By similarity).[RuleBase:RU003324]

Publication Abstract from PubMed

Membrane fusion is involved in many fundamental cellular processes and entry of enveloped viruses into host cells. Influenza type A virus HA has long served as a paradigm for mechanistic studies of protein-mediated membrane fusion via large-scale structural rearrangements induced by acidic pH. Here we report the newly determined crystal structure of influenza B virus HA2 in the postfusion state. Together with a large number of previously determined prefusion structures of influenza A and B virus HA and a postfusion structure of influenza A/H3N2 HA2, we identified conserved features that are shared between influenza A and B virus HA in the conformational transition and documented substantial differences that likely influence the detailed mechanisms of this process. Further studies are needed to dissect the effects of these and other structural differences in HA conformational changes and influenza pathogenicity and transmission, which may ultimately expedite the discovery of novel anti-influenza fusion inhibitors.

Structural insights into the membrane fusion mechanism mediated by influenza virus hemagglutinin.,Ni F, Chen X, Shen J, Wang Q Biochemistry. 2014 Feb 11;53(5):846-54. doi: 10.1021/bi401525h. Epub 2014 Jan 28. PMID:24433110^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Ni F, Chen X, Shen J, Wang Q. Structural insights into the membrane fusion mechanism mediated by influenza virus hemagglutinin. Biochemistry. 2014 Feb 11;53(5):846-54. doi: 10.1021/bi401525h. Epub 2014 Jan 28. PMID:24433110 doi:http://dx.doi.org/10.1021/bi401525h