Figure 1
The menaquinone pathway found in various species such as E. coli uses eight enzymes: MenA–MenH (coloured red). The newly found futalosine pathway uses Mqn enzymes to synthesize menaquinone (shown in black). A small divergence has been found for MqnB: species such as H. pylori and C. jejuni use 6-amino-6-deoxyfutalosine as a substrate (green), whereas S. coelicolor, T. thermophilus and A. cellulolyticus use the deaminase MqnX (blue) to process futalosine. |