Next Article in Journal
Oscillatoxin I: A New Aplysiatoxin Derivative, from a Marine Cyanobacterium
Next Article in Special Issue
The ADP-Ribosylating Toxins of Salmonella
Previous Article in Journal
Impact of Ergot Alkaloids on Female Reproduction in Domestic Livestock Species
Previous Article in Special Issue
CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in Bacillus cereus
Article Menu
Issue 6 (June) cover image

Export Article

Open AccessArticle

An In-Silico Sequence-Structure-Function Analysis of the N-Terminal Lobe in CT Group Bacterial ADP-Ribosyltransferase Toxins

Department of Molecular and Cellular Biology, University of Guelph, Guelph N1G 2W1, Canada
*
Author to whom correspondence should be addressed.
Toxins 2019, 11(6), 365; https://doi.org/10.3390/toxins11060365
Received: 30 May 2019 / Revised: 13 June 2019 / Accepted: 15 June 2019 / Published: 21 June 2019
(This article belongs to the Special Issue ADP-Ribosylating Toxin)
  |  
PDF [6694 KB, uploaded 21 June 2019]
  |  

Abstract

The C3-like toxins are single-domain proteins that represent a minimal mono-ADP-ribosyl transferase (mART) enzyme with a simple model scaffold for the entire cholera toxin (CT)-group. These proteins possess a single (A-domain) that modifies Rho proteins. In contrast, C2-like toxins require a binding/translocation partner (B-component) for intoxication. These are A-only toxins that contain the E-x-E motif, modify G-actin, but are two-domains with a C-domain possessing enzymatic activity. The N-domain of the C2-like toxins is unstructured, and its function is currently unknown. A sequence-structure-function comparison was performed on the N-terminal region of the mART domain of the enzymatic component of the CT toxin group in the CATCH fold (3.90.210.10). Special consideration was given to the N-domain distal segment, the α-lobe (α1–α4), and its different roles in these toxin sub-groups. These results show that the role of the N-terminal α-lobe is to provide a suitable configuration (i) of the α2–α3 helices to feature the α3-motif that has a role in NAD+ substrate binding and possibly in the interaction with the protein target; (ii) the α3–α4 helices to provide the α3/4-loop with protein-protein interaction capability; and (iii) the α1-Ntail that features specialized motif(s) according to the toxin type (A-only or A-B toxins) exhibiting an effect on the catalytic activity via the ARTT-loop, with a role in the inter-domain stability, and with a function in the binding and/or translocation steps during the internalization process. View Full-Text
Keywords: mono-ADP-ribosylation toxins; C3-like toxins; C2-like toxins; ADP-ribosylation; CT-toxins; target substrate motifs; N-terminal α-lobe mono-ADP-ribosylation toxins; C3-like toxins; C2-like toxins; ADP-ribosylation; CT-toxins; target substrate motifs; N-terminal α-lobe
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Lugo, M.R.; Merrill, A.R. An In-Silico Sequence-Structure-Function Analysis of the N-Terminal Lobe in CT Group Bacterial ADP-Ribosyltransferase Toxins. Toxins 2019, 11, 365.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Toxins EISSN 2072-6651 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top