Fig. 1: Biosynthesis of rhodoquinone and a structural model of RquA. | Communications Chemistry

Fig. 1: Biosynthesis of rhodoquinone and a structural model of RquA.

From: Microbial rhodoquinone biosynthesis proceeds via an atypical RquA-catalyzed amino transfer from S-adenosyl-L-methionine to ubiquinone

Fig. 1

a In select bacteria and protists, RquA converts ubiquinone (UQ, 1) to rhodoquinone (RQ, 2). b The amino acid sequence of RquA was aligned with related methyltransferases. Sequences of RquA from R. rubrum (R.r.); UbiE and UbiG from E. coli (E.c.); and, Coq3 and Coq5 from S. cerevisiae (S.c.) were aligned using Clustal Omega63. Characteristic S-adenosyl-L-methionine (SAM) binding motifs21 are indicated by light blue shading. D118 and D143 of RquA, which participate in interactions with SAM in related methyltransferases, are colored red and indicated with *. c An RquA model was predicted by AlphaFold264 using a Google co-laboratory webserver65 and visualized as a cartoon using PyMol (Schrödinger, LLC). The first 38 residues, which are not converged or predicted with high confidence by AlphaFold2, are omitted for clarity. α-Helices and β-sheets are colored cyan and magenta, respectively. Aspartic acid residues, D118 and D143, which potentially bind SAM, are colored red. d A surface representation is shown of the RquA model colored by a nonpolar-polar ratio (NPPR) as calculated using the Protein-Sol webserver66. A large hydrophobic patch (magenta) is present near the putative SAM-binding site.

Back to article page