Unique structure and function of viral rhodopsins
Unique structure and function of viral rhodopsins
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DOI：
10.1038/s41467-019-12718-0
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发表时间：
2019-10-30
影响因子：
16.6
通讯作者：
Gordeliy, Valentin
中科院分区：
文献类型：
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作者：
Bratanov, Dmitry;Kovalev, Kirill;Gordeliy, Valentin
最近，在大型双链DNA病毒中鉴定出两组视紫红质基因。病毒视紫红质的结构和功能尚不清楚。我们展示了第 2 组有机湖藻DNA病毒视紫红质 II (OLPVRII) 的功能表征和高分辨率结构。它形成五聚体，具有对称的瓶状中央通道，细胞质部分的狭窄前庭被 5 个精氨酸环覆盖，而 5 个苯丙氨酸在其出口处形成疏水屏障。质子供体E42位于螺旋B中。该结构在已知的视紫红质中是独特的。结构和功能数据以及分子动力学表明，OLPVRII 可能是类似于五聚体配体门控离子通道的光门控五聚体离子通道，然而，未来的膜片钳实验应该直接证明这一点。这些数据揭示了视紫红质的一个根本不同的分支，并可能有助于了解具有重要生态意义的海洋原生生物中的病毒与宿主的相互作用。
Recently, two groups of rhodopsin genes were identified in large double-stranded DNA viruses. The structure and function of viral rhodopsins are unknown. We present functional characterization and high-resolution structure of an Organic Lake Phycodnavirus rhodopsin II (OLPVRII) of group 2. It forms a pentamer, with a symmetrical, bottle-like central channel with the narrow vestibule in the cytoplasmic part covered by a ring of 5 arginines, whereas 5 phenylalanines form a hydrophobic barrier in its exit. The proton donor E42 is placed in the helix B. The structure is unique among the known rhodopsins. Structural and functional data and molecular dynamics suggest that OLPVRII might be a light-gated pentameric ion channel analogous to pentameric ligand-gated ion channels, however, future patch clamp experiments should prove this directly. The data shed light on a fundamentally distinct branch of rhodopsins and may contribute to the understanding of virus-host interactions in ecologically important marine protists.