Alr2954 of Anabaena sp. PCC 7120 with ADP-ribose pyrophosphatase activity bestows abiotic stress tolerance in Escherichia coli

Abstract

In silico derived properties on experimental validation revealed that hypothetical protein Alr2954 of Anabaena sp. PCC7120 is ADP-ribose pyrophosphatase, which belongs to nudix hydrolase superfamily. Presence of ADP-ribose binding site was attested by ADP-ribose pyrophosphatase activity (Km 44.71 ± 8.043 mM, Vmax 7.128 ± 0.417 μmol min−1 mg protein−1, and Kcat/Km 9.438 × 104 μM−1 min−1). Besides ADP-ribose, the enzyme efficiently hydrolyzed various nucleoside phosphatases such as 8-oxo-dGDP, 8-oxo-dADP, 8-oxo-dGTP, 8-oxo-dATP, GDP-mannose, ADP-glucose, and NADH. qRT-PCR analysis of alr2954 showed significant expression under different abiotic stresses reconfirming its role in stress tolerance. Thus, Alr2954 qualifies to be a member of nudix hydrolase superfamily, which serves as ADP-ribose pyrophosphatase and assists in multiple abiotic stress tolerance. © 2016, Springer-Verlag Berlin Heidelberg.