RAD51 Superfamily and RecA-like Superfamily II Helicases as Indicators of Phage Infection Strategy

• Zaina Punter, Biological Sciences, Delaware Technical Community College

• Shawn Polson, Associate Professor, Depts. of Computer & Information Sciences, Plant & Soil Sciences, Biological Sciences, University of Delaware
• Barbra Ferrell, , University of Delaware

Zaina Punter, Barbra D. Ferrell, Rachel A. Keown, Jeffry J. Fuhrman, K. Eric Wommack, Shawn W. Polson 

The world’s oceans contain tens of billions of bacteriophages, viruses that infect bacteria, making them one of the most abundant biological entities on Earth. While bacteriophages maintain a singular central function of genome replication, primarily through lytic or lysogenic infection strategies, the cumulative outcome of phage infection has significant impacts on microbial host communities and ecosystems. The Viral Ecology and Informatics Lab uses replication proteins, such as helicase, to identify and predict the infection strategy of unknown phage populations in metagenomic datasets.  This research project characterizes conserved domains and active sites in the RAD51 superfamily (RecA and UvsX) and RecA-like superfamily 2 helicases (RecG and UvrB), and uses this expert domain knowledge to validate helicases in environmental viral metagenomes (viromes). Bacterial and/or helicase protein sequences were acquired from UniProt, then annotated and aligned with Geneious. Important conserved and active sites were identified through a literature review and multiple sequence alignments. Putative helicases were retrieved from a collection of Rhode Island viromes based on homology to annotated references, and validated based on conservation of active sites. Future research will explore the diversity and abundance of RAD51 and RecA-like helicases and their potential use as markers of viral infection strategy and impacts on microbial communities.