Drastic changes in conformational dynamics of the antiterminator M2-1 regulate transcription efficiency in Pneumovirinae

作者：Leyrat Cedric; Renner Max; Harlos Karl; Huiskonen Juha T; Grimes Jonathan M^*

来源：eLife, 2014, 3: 02674.

DOI：10.7554/eLife.02674

`The M2-1 protein of human metapneumovirus (HMPV) is a zinc-binding transcription antiterminator which is highly conserved among pneumoviruses. We report the structure of tetrameric HMPV M2-1. Each protomer features a N-terminal zinc finger domain and an alpha-helical tetramerization motif forming a rigid unit, followed by a flexible linker and an alpha-helical core domain. The tetramer is asymmetric, three of the protomers exhibiting a closed conformation, and one an open conformation. Molecular dynamics simulations and SAXS demonstrate a dynamic equilibrium between open and closed conformations in solution. Structures of adenosine monophosphate-and DNA-bound M2-1 establish the role of the zinc finger domain in base-specific recognition of RNA. Binding to 'gene end' RNA sequences stabilized the closed conformation of M2-1 leading to a drastic shift in the conformational landscape of M2-1. We propose a model for recognition of gene end signals and discuss the implications of these findings for transcriptional regulation in pneumoviruses.

• 出版日期2014-5-19