Structure and function of Paramecium bursaria chlorella virus-1 encoded K+ channel Kcv

Kcv是在病毒中发现的第一个K+通道。它也是所有已知K+通道中最小和最原始的。由94个氨基酸组成的离子肽由双链DNA病毒PBVC-1编码，是病毒复制所必需的。在异源表达系统中，该蛋白质显示出从其他更复杂的K+通道已知的特征。这些包括离子选择性、电压依赖性和选择性阻断。结构简单性和功能复杂性的结合使该通道成为一个有前途的模型系统，用于检测功能性K+通道的最小结构要求。为此，我们将利用已知的高选择性压力施加在病毒基因组，这引起了广泛的家庭自然发生的K+通道同源物。同源物的分子分析和电生理学表征将鉴定保守的残基/结构域，其构成不同通道功能和结构的标志。

Kcv is the first K+ channel found in a virus. It is also the smallest and most primitive of all known K+ channels. The 94 amino acid lon peptide is encoded by the double stranded DNA virus PBVC-1 and is essential for viral replication. In heterologous expression systems the protein shows characteristic features known from other more complex K+ channels. These include ion selectivity, voltage dependency and selective block. The combination of structural simplicity and functional complexity makes this channel a promising model system for the detection of minimal structural requirements of functional K+ channels. For this purpose we will exploit the known high selective pressure exerted on viral genomes, which has given rise to a broad family of naturally occurring K+ channel homologues. Molecular analysis and electrophysiological characterization of the homologues will identify conserved residues/domains, which constitute hallmarks of diverse channel functions and structure.