Enzymic Adenosine Diphosphoribosylation of Nuclear Proteins

Abstract

Although it has been firmly established that nicotinamide adenine dinucleotide acts as a coenzyme in many biological oxidation-reduction reactions, this coenzyme has recently been found to participate in several other important biological processes. For example in uninfected Escherichia coli, a polynucleotide-joining reaction has been identified in which the pyrophosphate bond of NAD is hydrolyzed during the synthesis of phosphodiester bonds between the 5′-phosphoryl and 3′-hydroxyl termini of so-called “nicked” doublestranded DNA chains (Olivera and Lehman, 1967; Zimmerman et al., 1967; Gefter et al., 1967; Goulian et al., 1967). In the first step in this overall reaction the AMP moiety of NAD is transferred and covalently linked to the enzyme with the simultaneous release of nicotinamide mononucleotide (Little et al., 1967). In another class of reactions utilizing NAD, the nicotinamide moiety of NAD is removed and the remaining ADP-ribose portion is transferred to some acceptor protein molecule (Fig. 1). The reactions...