Terminase, capsid and portal proteins in candidate novel bacteriophages. (A) The Venn diagram shows, for each metagenomic project analyzed (marked with different shapes), the percentage of circular contigs identified by Seeker with different combinations of the three phage markers detected (color-coded). (B) Maximum percent identity across all three markers (terminase, capsid, and portal) and their closest known homologs, and that of the terminase separately, for each project. (C) The proportion of proteins with less than 50% identity to their closest known homologs for each of the three markers, and across all of the three markers combined (terminase, capsid and portal), shown separately for the four analyzed projects.