In Sulfolobus solfataricus, the Poly(ADP-Ribose) Polymerase-Like Thermoprotein Is a Multifunctional Enzyme

Autor: Anna De Maio, Elena Porzio, Sergio Rotondo, Anna Rita Bianchi, Maria Rosaria Faraone-Mennella
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Microorganisms, Vol 8, Iss 10, p 1523 (2020)
Druh dokumentu: article
ISSN: 2076-2607
DOI: 10.3390/microorganisms8101523
Popis: In Sulfolobus solfataricus, Sso, the ADP-ribosylating thermozyme is known to carry both auto- and heteromodification of target proteins via short chains of ADP-ribose. Here, we provide evidence that this thermoprotein is a multifunctional enzyme, also showing ATPase activity. Electrophoretic and kinetic analyses were performed using NAD+ and ATP as substrates. The results showed that ATP is acting as a negative effector on the NAD+-dependent reaction, and is also responsible for inducing the dimerization of the thermozyme. These findings enabled us to further investigate the kinetic of ADP-ribosylation activity in the presence of ATP, and to also assay its ability to work as a substrate. Moreover, since the heteroacceptor of ADP-ribose is the sulfolobal Sso7 protein, known as an ATPase, some reconstitution experiments were set up to study the reciprocal influence of the ADP-ribosylating thermozyme and the Sso7 protein on their activities, considering also the possibility of direct enzyme/Sso7 protein interactions. This study provides new insights into the ATP-ase activity of the ADP-ribosylating thermozyme, which is able to establish stable complexes with Sso7 protein.
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