Fig. 1: Characterization of MSTV1-like viruses retrieved in human and animal GIT.
From: Stable coexistence between an archaeal virus and the dominant methanogen of the human gut
a Geographical distribution of MSTV1. The map was created using the packages “maps” and “ggplot2” of R studio v.4.3.2106. b Proteomic tree of head-tailed viruses infecting methanogenic and hyperhalophilic archaea42. Families of viruses associated with methanogenic archaea are highlighted with colored background. Branch lengths are log-scaled and the branch length for family-level demarcation is around 0.05. MSTV1 is indicated in bold within the newly proposed virus family ‘Usuviridae’. c Alignment of MSTV1-like viruses originating from human and animal GIT. ORFs are depicted by arrows that indicate the direction of transcription. Functional annotations are shown above the corresponding ORFs. Homologous genes are depicted with the same colors and are connected by shading in grayscale, with intensity reflecting the amino acid sequence identity. Cdc6: AAA+ ATPase Orc1/Cdc6; HEPN: higher eukaryotes and prokaryotes nucleotide-binding domain-containing protein; int: integrase; MCP: major capsid protein; mCP: minor capsid protein; MTase: methyltransferase; NTN-hydrolase: N‐terminal nucleophile hydrolase; Prot: serine protease; RHH: ribbon-helix-helix protein; TAC: tail assembly chaperone; TerL: terminase large subunit; TerS: terminase small subunit; TMP: tail tape measure protein; TTP: tail tube protein; wHTH: winged helix-turn-helix domain; ZF: zinc finger domain-containing protein. d Schematic representation of a programmed −1 translational frameshift in the MCP sequence of MSTV1-like viruses, resulting in the translation of an Ig-like domain. The slippery sequence is boxed. e Structural models of the dominant and the Ig-like domain-containing frameshifted MSTV1 MCPs.
