Inorganic phosphate, arsenate, and vanadate enhance exonuclease transcript cleavage by RNA polymerase by 2000-fold.

ABSTRACT: Inorganic P_i is involved in all major biochemical pathways. Here we describe a previously unreported activity of P_i We show that P_i and its structural mimics, vanadate and arsenate, enhance nascent transcript cleavage by RNA polymerase (RNAP). They engage an Mg²⁺ ion in catalysis and activate an attacking water molecule. P_i, vanadate, and arsenate stimulate the intrinsic exonuclease activity of the enzyme nearly 2,000-fold at saturating concentrations of the reactant anions and Mg²⁺ This enhancement is comparable to that of specialized transcript cleavage protein factors Gre and TFIIS (3,000- to 4,000-fold). Unlike these protein factors, P_i and its analogs do not stimulate endonuclease transcript cleavage. Convers

SUBMITTER: Gottesman ME 

PROVIDER: S-EPMC5856549 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature