8rn3
Pseudo-symmetrical influenza B polymerase apo-dimer, encapsidase moiety (from "Influenza B polymerase pseudo-symmetrical dimer" | Local refinement)Pseudo-symmetrical influenza B polymerase apo-dimer, encapsidase moiety (from "Influenza B polymerase pseudo-symmetrical dimer" | Local refinement)
Structural highlights
FunctionPublication Abstract from PubMedReplication of influenza viral RNA depends on at least two viral polymerases, a parental replicase and an encapsidase, and cellular factor ANP32. ANP32 comprises an LRR domain and a long C-terminal low complexity acidic region (LCAR). Here we present evidence suggesting that ANP32 is recruited to the replication complex as an electrostatic chaperone that stabilises the encapsidase moiety within apo-polymerase symmetric dimers that are distinct for influenza A and B polymerases. The ANP32 bound encapsidase, then forms the asymmetric replication complex with the replicase, which is embedded in a parental ribonucleoprotein particle (RNP). Cryo-EM structures reveal the architecture of the influenza A and B replication complexes and the likely trajectory of the nascent RNA product into the encapsidase. The cryo-EM map of the FluB replication complex shows extra density attributable to the ANP32 LCAR wrapping around and stabilising the apo-encapsidase conformation. These structures give new insight into the various mutations that adapt avian strain polymerases to use the distinct ANP32 in mammalian cells. Structures of influenza A and B replication complexes give insight into avian to human host adaptation and reveal a role of ANP32 as an electrostatic chaperone for the apo-polymerase.,Arragain B, Krischuns T, Pelosse M, Drncova P, Blackledge M, Naffakh N, Cusack S Nat Commun. 2024 Aug 19;15(1):6910. doi: 10.1038/s41467-024-51007-3. PMID:39160148[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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