“…With reference to metabolic engineering, we must add a final comment to the understanding of this stage of the MSP. As a consequence of its pervasive presence, MTA regulates, directly or indirectly, expression, activity or both, of enzymes involved in methionine, AdoMet or polyamine biosynthesis (Anashkin et al, 2017). Being similar to AdoMet, but smaller, MTA often interferes with AdoMet synthesis or other processes (see for example Pang et al, 2017), with a variety of consequences on methionine availability, including inhibition of virulence of pathogens and production of antibiotics (Tojo et al, 2014;Wang et al, 2017;Bourgeois et al, 2018).…”