Structural and functional analyses of the N-terminal domain of the A subunit of a Bacillus megaterium spore germinant receptor
Abstract
Germination of Bacillus spores is induced by the interaction of specific nutrient molecules with germinant receptors (GRs) localized in the spore’s inner membrane. GRs typically consist of three subunits referred to as A, B, and C, although functions of individual subunits are not known. Here we present the crystal structure of the N-terminal domain (NTD) of the A subunit of the Bacillus megaterium GerK 3 GR, revealing two distinct globular subdomains bisected by a cleft, a fold with strong homology to substrate-binding proteins in bacterial ABC transporters. Molecular docking, chemical shift perturbation measurement, and mutagenesis coupled with spore germination analyses support a proposed model that the interface between the two subdomains in the NTD of GR A subunits serves as the germinant binding site and plays a critical role in spore germination. Our findings provide a conceptual framework for understanding the germinant recruitment mechanism by which GRs trigger spore germination.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 21, 2019
- Source ID
- 10.1073/pnas.1903675116
Entities
People
- Abigail Perez-valdespino
- Andrew K Davis
- Bing Hao
- Kai Jin
- Kyle Federkiewicz
- Mark W. Maciejewski
- Peter Setlow
- Yunfeng Li
Organizations
- National Institute of General Medical Sciences
- United States Department of Defense
- University of Connecticut Health Center