Biochemical Characterization of an Arabinoside Monophosphate Specific 5'-Nucleotidase-like Enzyme from .
Yuxue Liu, Xiaobei Liu, Xiaojing Zhang, Xiaoting Tang, Weiwei Su, Zhenyu Wang, Hailei Wang
Author Information
Yuxue Liu: Henan Engineering Research Center of Bioconversion Technology of Functional Microbes, College of Life Science, Henan Normal University, Xinxiang 453007, China.
Xiaobei Liu: Henan Engineering Research Center of Bioconversion Technology of Functional Microbes, College of Life Science, Henan Normal University, Xinxiang 453007, China.
Xiaojing Zhang: Henan Engineering Research Center of Bioconversion Technology of Functional Microbes, College of Life Science, Henan Normal University, Xinxiang 453007, China.
Xiaoting Tang: Henan Engineering Research Center of Bioconversion Technology of Functional Microbes, College of Life Science, Henan Normal University, Xinxiang 453007, China.
Weiwei Su: Henan Engineering Research Center of Bioconversion Technology of Functional Microbes, College of Life Science, Henan Normal University, Xinxiang 453007, China.
Zhenyu Wang: Henan Engineering Research Center of Bioconversion Technology of Functional Microbes, College of Life Science, Henan Normal University, Xinxiang 453007, China.
Hailei Wang: Henan Engineering Research Center of Bioconversion Technology of Functional Microbes, College of Life Science, Henan Normal University, Xinxiang 453007, China.
To investigate the function of the gene in the pentostatin and vidarabine (Ara-A) biosynthetic gene cluster in NRRL 3238, PenF was recombinantly expressed and characterized. Enzymatic characterization of the enzyme demonstrated that PenF exhibited Metal-dependent nucleoside 5'-monophosphatase activity, showing a substrate preference for arabinose nucleoside 5'-monophosphate over 2'-deoxyribonucleoside 5'-monophosphate and ribonucleoside 5'-monophosphate. Metal ions such as Mg and Mn significantly enhanced enzyme activity, whereas Zn, Cu, and Ca inhibited it. For vidarabine 5'-monophosphate, the and values were determined to be 71.5 μM and 33.9 min, respectively. The value was 474.1 mM·min for vidarabine 5-monophosphate and was 68-fold higher than that for 2'-deoxyadenosine 5'-monophosphate. Comparative sequence alignment and structural studies suggested that residues outside the primary substrate-binding site are responsible for this substrate specificity. In conclusion, PenF's activity toward vidarabine 5'-monophosphate likely plays a role in the dephosphorylation of precursors during Ara-A biosynthesis.
