Open AccessInteraction with adenylate cyclase toxin from Bordetella pertussis affects the metal binding properties of calmodulin
Author(s) -
Springer Tzvia I.,
Emerson Corey C.,
Johns Christian W.,
Finley Natosha L.
Publication year - 2017
Publication title -
febs open bio
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.718
H-Index - 31
ISSN - 2211-5463
DOI - 10.1002/2211-5463.12138
Subject(s) - adenylate cyclase toxin , bordetella pertussis , adenylate kinase , calmodulin , cyclase , chemistry , pertussis toxin , biochemistry , binding site , biophysics , biology , enzyme , bacteria , signal transduction , g protein , genetics
Adenylate cyclase toxin domain (CyaA‐ACD) is a calmodulin (CaM)‐dependent adenylate cyclase involved in Bordetella pertussis pathogenesis. Calcium (Ca 2+ ) and magnesium (Mg 2+ ) concentrations impact CaM‐dependent CyaA‐ACD activation, but the structural mechanisms remain unclear. In this study, NMR, dynamic light scattering, and native PAGE were used to probe Mg 2+ ‐induced transitions in CaM's conformation in the presence of CyaA‐ACD. Mg 2+ binding was localized to sites I and II, while sites III and IV remained Ca 2+ loaded when CaM was bound to CyaA‐ACD. 2Mg 2+ /2Ca 2+ ‐loaded CaM/CyaA‐ACD was elongated, whereas mutation of site I altered global complex conformation. These data suggest that CyaA‐ACD interaction moderates CaM's Ca 2+ ‐ and Mg 2+ ‐binding capabilities, which may contribute to pathobiology.