Download MendeleyMapping the DNA-Binding Motif of Scabin Toxin, a Guanine Modifying Enzyme from Streptomyces scabies .
Vatta, M., Lyons, B., Heney, K.A., Lidster, T., Merrill, A.R.(2021) Toxins (Basel) 13
- PubMed: 33450958
- DOI: https://doi.org/10.3390/toxins13010055
- Primary Citation of Related Structures:
6VPA, 6VUV, 6VV4, 6VVF - PubMed Abstract:
Scabin is a mono-ADP-ribosyltransferase toxin/enzyme and possible virulence factor produced by the agriculture pathogen, Streptomyces scabies . Recently, molecular dynamic approaches and MD simulations revealed its interaction with both NAD + and DNA substrates. An Essential Dynamics Analysis identified a crab-claw-like mechanism, including coupled changes in the exposed motifs, and the R β1 -R La -N Lc -STT β2 -W PN -W ARTT -(QxE) ARTT sequence motif was proposed as a catalytic signature of the Pierisin family of DNA-acting toxins. A new fluorescence assay was devised to measure the kinetics for both RNA and DNA substrates. Several protein variants were prepared to probe the Scabin-NAD-DNA molecular model and to reveal the reaction mechanism for the transfer of ADP-ribose to the guanine base in the DNA substrate. The results revealed that there are several lysine and arginine residues in Scabin that are important for binding the DNA substrate; also, key residues such as Asn110 in the mechanism of ADP-ribose transfer to the guanine base were identified. The DNA-binding residues are shared with ScARP from Streptomyces coelicolor but are not conserved with Pierisin-1, suggesting that the modification of guanine bases by ADP-ribosyltransferases is divergent even in the Pierisin family.
Organizational Affiliation:
Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
