Fig. 1: Diversity of Asgard archaeal Argonautes and a deep-branching PIWI-clade HrAgo1.
From: RNA-guided RNA silencing by an Asgard archaeal Argonaute
a Maximum-likelihood phylogenetic analysis of the MID-PIWI domains of Argonaute proteins showing that asAgos are polyphyletic. HrAgo1 is phylogenetically related to Argonautes in the eukaryotic PIWI clade. 334 representative sequences and 572 sites were analyzed using IQ-TREE based on Q.pfam + C60 + F + G4 model. Color pallets indicate host classification, outer ring indicate pAgo and eAgo classifications. Ultrafast bootstrap 2 (UFBoot2) values above 95, calculated based on 1000 replicates, are shown in gray circles. HrAgo1, HrAgo2, and the UFBoot2 values at the branches are highlighted. Inset, Maximum-likelihood phylogenetic analysis based on the MID-PIWI domains with a broader sampling of AGO and PIWI indicates that HrAgo1 is sister to all eukaryotic PIWIs. UFBoot2 values calculated based on 1000 replicates are indicated. b Fraction of Argonaute-encoding genomes in different prokaryotic phyla. The tree topology was adapted from GTDB v207 by removing phyla with less than 40 representatives. Source data are provided in the Source data file. c Genomic depiction of Asgard archaeon ‘Ca. H. repetitus’, where the genes encoding 16S and 23S rRNA, origin of replication protein Cdc6, and putative immune systems are indicated. The synteny and predicted domain compositions of genes surrounding pAgo-encoding genes are highlighted. RM, restriction-modification system. Blue bars indicate two genome assembly gaps with undetermined sequences.
