Open AccessA noncanonical cytochrome c stimulates calcium binding by PilY1 for type IVa pili formation
Author(s) -
Marco Herfurth,
Anke Treuner-Lange,
Timo Glatter,
Nadine Wittmaack,
Egbert Hoiczyk,
Antonio J. Pierik,
Lotte SøgaardAndersen
Publication year - 2022
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2115061119
Subject(s) - pilus , myxococcus xanthus , pilin , biology , fimbriae proteins , biochemistry , calcium , heme , adhesion , fimbria , microbiology and biotechnology , biophysics , chemistry , escherichia coli , mutant , gene , enzyme , organic chemistry
Significance Type IVa pili (T4aP) are bacterial surface structures that function under different environmental conditions. In the machine for T4aP formation, a complex of minor pilins and PilY1 primes T4aP formation and is also present at the pilus tip mediating adhesion. Similar to several other bacterial adhesins, PilY1 depends on calcium binding for function. Here, we demonstrate that inMyxococcus xanthus, PilY1 at low levels of calcium depends on the accessory protein TfcP to bind calcium, thereby stabilizing the protein. TfcP is a noncanonical cytochromec that does not participate in electron transport. Rather our data support that TfcP interacts transiently with PilY1 to stimulate calcium binding. In this way, TfcP expands the range of calcium levels under which T4aP functions.