Comparative genomics reveals electron transfer and syntrophic mechanisms differentiating methanotrophic and methanogenic archaea
Fig 5
(A) Amino acid sequence identity of MetF homologs found in ANME, “Ca. Argoarchaeum” and “Ca. Syntrophoarchaeum.” ANME-1 and “Ca. Syntrophoarchaeum” form one cluster based on sequence similarity, while ANME-2a, ANME-2b, ANME-2d, ANME-3, and “Ca. Argoarchaeum” form a second. Grayscale values represent percent identity. Sequences similar to the ANME-2/3 or ANME-1 clusters were retrieved via BLAST search of the NCBI nr database and used to construct phylogenetic trees of these 2 groups. (B) ANME-2, ANME-3, and “Ca. Argoarchaeum” cluster together with closely related members of the Methanosarcinaceae. (C) ANME-1 and “Ca. Syntrophoarchaeum” form a polyphyletic group within a diverse group of sequences derived from MAGs of uncultured archaea. Notably, the ANME-1 sp. SA is significantly different than the rest of the ANME-1. Roots for both trees lead to closely related MetF sequences from bacteria. Branch support values of 100% are labeled with closed circles, >50% with open circles. Tree scales represent substitutions per site. Tree construction parameters are found in the Materials and methods section. Alignments and tree files can be found in S1 Data. ANME, anaerobic methanotrophic; MAG, metagenome-assembled genome; MetF, methylenetetrahydrofolate reductase.