Viruses infecting marine picoplancton encode functional potassium ion channels

Authors

Fenja Siotto, Technische Universität Darmstadt
Corinna Martin, Technische Universität Darmstadt
Oliver Rauh, Technische Universität Darmstadt
James L. Van Etten, University of Nebraska-LincolnFollow
Indra Schroeder, Technische Universität Darmstadt
Anna Moroni, Dipartimento di Biologia Università degli Studi di Milano e Istituto di Biofisica
Gerhard Thiel, Technische Universität DarmstadtFollow

ORCID IDs

James L. Van Etten

Document Type

Article

Date of this Version

2014

Citation

Virology 466–467 (October 2014; Special issue: Giant Viruses), pp. 103–111; doi: 10.1016/j.virol.2014.05.002

Comments

Copyright © 2014 Elsevier Inc. Used by permission.

Abstract

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.