Identification of the ternary complex of ribonuclease HI:RNA/DNA hybrid:metal ions by ESI mass spectrometry.

ABSTRACT: Ribonuclease HI, an endoribonuclease, catalyzes the hydrolysis of the RNA strand of an RNA/DNA hybrid and requires divalent metal ions for its enzymatic activity. However, the mechanistic details of the activity of ribonuclease HI and its interaction with divalent metal ions remain unclear. In this study, we performed real-time monitoring of the enzyme-substrate complex in the presence of divalent metal ions (Mn²⁺ or Zn²⁺) using electrospray ionization-mass spectrometry (ESI-MS). The findings provide clear evidence that the enzymatic activity of the ternary complex requires the binding of two divalent metal ions. The Zn²⁺ ions bind to both the enzyme itself and the enzyme:substrate complex more strongly than Mn²⁺ ions, and gives, in part, the ter

SUBMITTER: Ando T 

PROVIDER: S-EPMC8042393 | biostudies-literature | 2021 Jan-Jun

REPOSITORIES: biostudies-literature