Adenylate-Forming Enzymes of Rubradirin Biosynthesis: RubC1 Is a Bifunctional Enzyme with Aminocoumarin Acyl Ligase and Tyrosine-Activating Domains

The aminoshikimic acid pathway in bacteria as source of precursors for the synthesis of antibacterial and antiviral compounds

The aminoshikimic acid (ASA) pathway comprises a series of reactions resulting in the synthesis of 3-amino-5-hydroxybenzoic acid (AHBA), present in bacteria such as Amycolatopsis mediterranei and Streptomyces. AHBA is the precursor for synthesizing the mC₇N units, the characteristic structural component of ansamycins and mitomycins antibiotics, compounds with important antimicrobial and anticancer activities. Furthermore, aminoshikimic acid, another relevant intermediate of the ASA pathway, is an attractive candidate for a precursor for oseltamivir phosphate synthesis, the most potent anti-influenza neuraminidase inhibitor treatment of both seasonal and pandemic influenza. This review discusses the relevance of the key intermediate AHBA as a scaffold molecule to synthesize diverse ansamycins and mitomycins. We describe the structure and control of the expression of the model biosynthetic cluster rif in A. mediterranei to synthesize ansamycins and review several current pharmaceutical applications of these molecules. Additionally, we discuss some relevant strategies developed for overproducing these chemicals, focusing on the relevance of the ASA pathway intermediates kanosamine, AHAB, and ASA.