Backbone assignment of the N-terminal domain of the A subunit of the Bacillus cereus GerI germinant receptor.

The nutrient germinant receptors (GRs) in spores of Bacillus species consist of a cluster of three proteins- designated A, B, and C subunits- that play a critical role in initiating the germination of dormant spores in response to specific nutrient molecules. The Bacillus cereus GerI GR is essential for inosine-induced germination; however, the roles of the individual subunits and the mechanism by which germinant binding activates GR function remain unclear. In this study, we report the backbone chemical shift assignments of the N-terminal domain (NTD) of the A subunit of GerI (GerIA^NTD). Furthermore, we derive the secondary structure of GerIA^NTD in solution and compare it with the crystal structure of the NTD of the A subunit of a Bacillus megaterium GR. These findings lay the foundation for further NMR studies aimed at investigating the structure-function relationship of the GerI subunits, with a broader goal of understanding the molecular mechanism underlying germinant recognition and signal transduction in GRs across Bacillus species.