8BE0

Early transcription elongation state of influenza B/Mem polymerase backtracked due to double incoproation of nucleotide analogue T1106 and with singly incoporated T1106 at the C +1 position

8BE0 の概要

• エントリーDOI: 10.2210/pdb8be0/pdb
• 関連するPDBエントリー: 7QTL
• EMDBエントリー: 15996
• 分子名称: Polymerase acidic protein, RNA-directed RNA polymerase catalytic subunit, Polymerase basic protein 2, ... (9 entities in total)
• 機能のキーワード: influenza, viral rna-dependent rna polymerase; antiviral drug; nucleoside analogue; t705 (favipiravir); t1106; cap-dependent transcription; backtracking;, viral protein
• 由来する生物種: Influenza B virus (B/Memphis/13/2003); 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 281212.48

構造登録者

Cusack, S.,Kouba, T. (登録日: 2022-10-20, 公開日: 2022-12-28, 最終更新日: 2025-07-09)

主引用文献

Kouba, T.,Dubankova, A.,Drncova, P.,Donati, E.,Vidossich, P.,Speranzini, V.,Pflug, A.,Huchting, J.,Meier, C.,De Vivo, M.,Cusack, S.
Direct observation of backtracking by influenza A and B polymerases upon consecutive incorporation of the nucleoside analog T1106.
Cell Rep, 42:111901-111901, 2023

PubMed Abstract: The antiviral pseudo-base T705 and its de-fluoro analog T1106 mimic adenine or guanine and can be competitively incorporated into nascent RNA by viral RNA-dependent RNA polymerases. Although dispersed, single pseudo-base incorporation is mutagenic, consecutive incorporation causes polymerase stalling and chain termination. Using a template encoding single and then consecutive T1106 incorporation four nucleotides later, we obtained a cryogenic electron microscopy structure of stalled influenza A/H7N9 polymerase. This shows that the entire product-template duplex backtracks by 5 nt, bringing the singly incorporated T1106 to the +1 position, where it forms an unexpected T1106:U wobble base pair. Similar structures show that influenza B polymerase also backtracks after consecutive T1106 incorporation, regardless of whether prior single incorporation has occurred. These results give insight into the unusual mechanism of chain termination by pyrazinecarboxamide base analogs. Consecutive incorporation destabilizes the proximal end of the product-template duplex, promoting irreversible backtracking to a more energetically favorable overall configuration.

PubMed: 36596301
DOI: 10.1016/j.celrep.2022.111901

実験手法

ELECTRON MICROSCOPY (2.34 Å)