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Publication Abstract from PubMed

Lassa virus is endemic in West Africa and can cause severe hemorrhagic fever. The viral L protein transcribes and replicates the RNA genome via its RNA-dependent RNA polymerase activity. Here, we present nine cryo-EM structures of the L protein in the apo-, promoter-bound pre-initiation and active RNA synthesis states. We characterize distinct binding pockets for the conserved 3' and 5' promoter RNAs and show how full-promoter binding induces a distinct pre-initiation conformation. In the apo- and early elongation states, the endonuclease is inhibited by two distinct L protein peptides, whereas in the pre-initiation state it is uninhibited. In the early elongation state, a template-product duplex is bound in the active site cavity together with an incoming non-hydrolysable nucleotide and the full C-terminal region of the L protein, including the putative cap-binding domain, is well-ordered. These data advance our mechanistic understanding of how this flexible and multifunctional molecular machine is activated.

Conformational changes in Lassa virus L protein associated with promoter binding and RNA synthesis activity.,Kouba T, Vogel D, Thorkelsson SR, Quemin ERJ, Williams HM, Milewski M, Busch C, Gunther S, Grunewald K, Rosenthal M, Cusack S Nat Commun. 2021 Dec 2;12(1):7018. doi: 10.1038/s41467-021-27305-5. PMID:34857749^[1]

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