Abstract
Pseudomonas aeruginosa exoenzyme S is an adenosine diphosphate ribosyltransferase distinct from Pseudomonas toxin A. Exoenzyme S catalyzes the transfer of radioactivity from all portions of radiolabeled NAD+ except nicotinamide. Digestion of the radiolabeled product(s) formed in the presence of [adenine-14C]NAD+ and exoenzyme S with snake venom phosphodiesterase yields only AMP, suggesting that ADP-ribose is present as monomers and not as poly(ADP-ribose). Exoenzyme S does not catalyze the transfer of ADP-ribose from NAD+ to elongation factor 2, as do toxin A and diphtheria toxin, but to one or more other proteins present in crude extracts of wheat germ or rabbit reticulocytes and in partially purified preparations of elongation factor I. The ADP-ribosyltransferase activity of exoenzyme S is distinct from toxin A by several tests: it is not neutralized by toxin A antibody, it is destroyed rather than potentiated by pretreatment with urea, and it is more heat stable. These latter observations and the substrate specificity suggest that exoenzyme S is different from any previously described prokaryotic ADP-ribosyltransferase.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
