The cytoplasmic C-terminal tail of the matrix protein 2 (M2) from influenza A virus has a well conserved sequence and is involved in interactions with several host proteins as well as the influenza matrix protein 1 (M1). Whereas the transmembrane domain of M2 has been well characterised structurally and functionally, high resolution information about the distal cytoplasmic tail is lacking. Here we report the chemical shifts of the cytoplasmic tail of M2 and the chemical shift perturbations at low pH and in the presence of membrane mimetics. The cytoplasmic tail residues are mostly disordered but an extended backbone conformation is adopted by the LC3 binding motif and the putative M1 interaction site has partial helical content with a small pH-dependence. The chemical shift assignments provide a basis for further investigations into interactions of the M2 cytoplasmic tail with viral and host cell factors.

中文翻译：

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pH依赖的甲型流感病毒M2细胞质尾巴的二级结构倾向。

来自甲型流感病毒的基质蛋白2（M2）的细胞质C末端尾巴具有良好保守的序列，并参与与几种宿主蛋白​​以及流感基质蛋白1（M1）的相互作用。尽管已经在结构和功能上很好地表征了M2的跨膜结构域，但缺乏有关远端细胞质尾巴的高分辨率信息。在这里，我们报告M2的细胞质尾部的化学位移和在低pH和存在膜模拟物的情况下的化学位移扰动。细胞质的尾巴残基大多是无序的，但LC3结合基序采用了扩展的骨架构象，推定的M1相互作用位点具有部分螺旋含量，对pH的依赖性较小。