Shaotong Zhou1, Xiaotang Chen1, Xianpu Ni2, Yu Liu1, Hui Zhang1, Min Dong3, Huanzhang Xia4. 1. School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Benxi, 117004, China. 2. School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Benxi, 117004, China. nixianpu126@126.com. 3. Frontiers Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China. mindong@tju.edu.cn. 4. School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Benxi, 117004, China. hzxia@syphu.edu.cn.
Abstract
BACKGROUND: The 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. RESULTS: Here, 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. CONCLUSIONS: This 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.
BACKGROUND: The 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. RESULTS: Here, 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. CONCLUSIONS: This 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.