Next Article in Journal
T-2 Toxin/HT-2 Toxin and Ochratoxin A ELISAs Development and In-House Validation in Food in Accordance with Commission Regulation (EU) No 519/2014
Previous Article in Journal
Targeting Metastasis with Snake Toxins: Molecular Mechanisms
Previous Article in Special Issue
Membrane-Active Properties of an Amphitropic Peptide from the CyaA Toxin Translocation Region
Article Menu
Issue 12 (December) cover image

Export Article

Open AccessFeature PaperCommunication
Toxins 2017, 9(12), 389; doi:10.3390/toxins9120389

Site I Inactivation Impacts Calmodulin Calcium Binding and Activation of Bordetella pertussis Adenylate Cyclase Toxin

1
Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056, USA
2
Department of Microbiology, Miami University, Oxford, OH 45056, USA
*
Author to whom correspondence should be addressed.
Academic Editor: Alexandre Chenal
Received: 8 November 2017 / Revised: 26 November 2017 / Accepted: 27 November 2017 / Published: 30 November 2017
(This article belongs to the Special Issue Adenylate Cyclase (CyaA) Toxin)
View Full-Text   |   Download PDF [1381 KB, uploaded 30 November 2017]   |  

Abstract

Site I inactivation of calmodulin (CaM) was used to examine the importance of aspartic acid 22 at position 3 in CaM calcium binding, protein folding, and activation of the Bordetella pertussis adenylate cyclase toxin domain (CyaA-ACD). NMR calcium titration experiments showed that site I in the CaM mutant (D22A) remained largely unperturbed, while sites II, III, and IV exhibited calcium-induced conformational changes similar to wild-type CaM (CaMWt). Circular dichroism analyses revealed that D22A had comparable α-helical content to CaMWt, and only modest differences in α-helical composition were detected between CaMWt-CyaA-ACD and D22A-CyaA-ACD complexes. However, the thermal stability of the D22A-CyaA-ACD complex was reduced, as compared to the CaMWt-CyaA-ACD complex. Moreover, CaM-dependent activity of CyaA-ACD decreased 87% in the presence of D22A. Taken together, our findings provide evidence that D22A engages CyaA-ACD, likely through C-terminal mediated binding, and that site I inactivation exerts functional effects through the modification of stabilizing interactions that occur between N-terminal CaM and CyaA-ACD. View Full-Text
Keywords: calcium; calmodulin; CyaA toxin; NMR calcium; calmodulin; CyaA toxin; NMR
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).

Supplementary material

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Johns, C.W.; Finley, N.L. Site I Inactivation Impacts Calmodulin Calcium Binding and Activation of Bordetella pertussis Adenylate Cyclase Toxin. Toxins 2017, 9, 389.

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