Viruses infecting marine picoplancton encode functional potassium ion channels

• Published in: Virology
• Main Authors: Siotto, Fenja, Martin, Corinna, Rauh, Oliver, Van Etten, James L., Schroeder, Indra, Moroni, Anna, Thiel, Gerhard
• Other Authors: F. Siotto, C. Martin, O. Rauh, J.L. Van Etten, I. Schroeder, A. Moroni, G. Thiel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Academic Press Inc. 2014
• Subjects: K+ channel evolution; Kcv; Chlorella viruse; Algal viruse; Virus evolution; Settore BIO/04 - Fisiologia Vegetale; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/2434/585472; https://doi.org/10.1016/j.virol.2014.05.002

Phycodnaviruses are dsDNA viruses, which infect algae. Their large genomes encode many gene products, like small K+channels, with homologs in prokaryotes and eukaryotes. Screening for K+channels revealed their abundance in viruses from fresh-water habitats. Recent sequencing of viruses from marine algae or from salt water in Antarctica revealed sequences with the predicted characteristics of K+channels but with some unexpected features. Two genes encode either 78 or 79 amino acid proteins, which are the smallest known K+channels. Also of interest is an unusual sequence in the canonical α-helixes in K+channels. Structural prediction algorithms indicate that the new channels have the conserved α-helix folds but the algorithms failed to identify the expected transmembrane domains flanking the K+channel pores. In spite of these unexpected properties electophysiological studies confirmed that the new proteins are functional K+channels.