Fig. 1: Pathways and genes involved in guanidine degradation.
a, The guanidine carboxylase pathway. AH, allophanate hydrolase; CD, carboxyguanidine deaminase; Gase, guanidinase; GC, guanidine carboxylase; Pi, inorganic phosphate; Uase, urease. b, The guanidinase pathway. c, Arrangements of genes encoding proteins involved in guanidine degradation under the regulation of type I guanidine riboswitches in the comammox microorganism N. inopinata, the AOB Nitrosospira multiformis and two bacterial model organisms for guanidine catabolism. Each of the four genomes also encodes urease (not displayed) at locations that are not regulated by guanidine riboswitches.
