A diadenosine 5 ',5 ''-p(1)p(4) tetraphosphate (AP(4)A) hydrolase from Arabidopsis thaliana that is activated preferentially by Mn2+ ions

作者：Szurmak Blanka; Wyslouch Cieszynska Aleksandra; Wszelaka Rylik Malgorzata; Bal Wojciech; Dobrzanska Marta^*

来源：Acta Biochimica Polonica, 2008, 55(1): 151-160.

• Ap(4)A hydrolase
• Nudix
• manganese
• Arabidopsis thaliana

Asymmetrical diadenosine 5',5 ''-(PP4)-P-1 tetraphosphate (Ap(4)A) hydrolases are key enzymes controlling the in vivo concentration of AP(4)A - an important signaling molecule involved in regulation of DNA replication and repair, signaling in stress response and apoptosis. Sequence homologies indicate that the genome of the model plant Arabidopsis thaliana contains at least three open reading frames encoding presumptive Ap(4)A hydrolases: At1g30110, At3g10620, and At5g06340. In this work we present efficient overexpression and detailed biochemical characteristics of the AtNUDX25 protein encoded by the At1g30110 gene. Aided by the determination of the binding constants of Mn(AP(4)A) and Mg(Ap(4)A) complexes using isothermal titration calorimetry (ITC) we show that AtNUDX25 preferentially hydrolyzes Ap(4)A in the form of a Mn2+ complex.

• 出版日期2008