Abstract
BackgroundThe C-3′,4′-dideoxygenation structure in gentamicin can prevent deactivation by aminoglycoside 3′-phosphotransferase (APH(3′)) in drug-resistant pathogens. However, the enzyme catalyzing the dideoxygenation step in the gentamicin biosynthesis pathway remains unknown.ResultsHere, we report that GenP catalyzes 3′ phosphorylation of the gentamicin biosynthesis intermediates JI-20A, JI-20Ba, and JI-20B. We further demonstrate that the pyridoxal-5′-phosphate (PLP)-dependent enzyme GenB3 uses these phosphorylated substrates to form 3′,4′-dideoxy-4′,5′-ene-6′-oxo products. The following C-6′-transamination and the GenB4-catalyzed reduction of 4′,5′-olefin lead to the formation of gentamicin C. To the best of our knowledge, GenB3 is the first PLP-dependent enzyme catalyzing dideoxygenation in aminoglycoside biosynthesis.ConclusionsThis discovery solves a long-standing puzzle in gentamicin biosynthesis and enriches our knowledge of the chemistry of PLP-dependent enzymes. Interestingly, these results demonstrate that to evade APH(3′) deactivation by pathogens, the gentamicin producers evolved a smart strategy, which utilized their own APH(3′) to activate hydroxyls as leaving groups for the 3′,4′-dideoxygenation in gentamicin biosynthesis.
Highlights
The C-3′,4′-dideoxygenation structure in gentamicin can prevent deactivation by aminoglycoside 3′-phosphotransferase (APH(3′)) in drug-resistant pathogens
We demonstrate that the phosphorylation catalyzed by GenP is the first step in the gentamicin C-3′,4′-dideoxygenation process
GenP starts the C‐3′,4′‐dideoxygenation process in the gentamicin biosynthetic pathway To investigate the function of GenP in gentamicin biosynthesis, the intermediate metabolites of the biosynthetic pathway, JI-20A, JI-20Ba, and JI-20B were used as substrates
Summary
The C-3′,4′-dideoxygenation structure in gentamicin can prevent deactivation by aminoglycoside 3′-phosphotransferase (APH(3′)) in drug-resistant pathogens. The enzyme catalyzing the dideoxygenation step in the gentamicin biosynthesis pathway remains unknown. Aminoglycoside antibiotics (AGAs) have been available for clinical use since the 1940s and have been shown to exhibit broad-spectrum activities [1]. The spread of resistance is limiting their use in the clinic, which is primarily induced by aminoglycoside-modifying enzymes (AMEs). Gentamicin is a broad-spectrum aminoglycoside bactericidal antibiotic produced by Micromonospora echinospora with a C-3′,4′-dideoxygenation moiety. The enzymatic steps that lead to the pseudotrisaccharide gentamicins JI-20A, JI-20Ba, and JI-20B have all been elucidated. They are the starting compounds of the C-3′,4′-dideoxygenation biosynthetic process. Little detailed information of the featured C-3′,4′-dideoxygenation process is available (Fig. 2)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
