RT Journal Article
SR Electronic
T1 Dormant spores sense amino acids through the B subunits of their germination receptors
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.10.28.466322
DO 10.1101/2021.10.28.466322
A1 Lior Artzi
A1 Assaf Alon
A1 Kelly P. Brock
A1 Anna G. Green
A1 Amy Tam
A1 Fernando H. Ramírez-Guadiana
A1 Debora Marks
A1 Andrew Kruse
A1 David Z. Rudner
YR 2021
UL http://biorxiv.org/content/early/2021/10/28/2021.10.28.466322.abstract
AB Bacteria from the orders Bacillales and Clostridiales differentiate into stress-resistant spores that can remain dormant for years, yet rapidly germinate upon nutrient sensing. How spores monitor nutrients is poorly understood but in most cases requires putative membrane receptors. The prototypical receptor from Bacillus subtilis consists of three proteins (GerAA, GerAB, GerAC) required for germination in response to L-alanine. GerAB belongs to the Amino Acid-Polyamine-Organocation superfamily of transporters. Using evolutionary co-variation analysis, we provide evidence that GerAB adopts a structure similar to an L-alanine transporter from this superfamily. We show that mutations in gerAB predicted to disrupt the ligand-binding pocket impair germination, while mutations predicted to function in L-alanine recognition enable spores to respond to L-leucine or L-serine. Finally, substitutions of bulkier residues at these positions cause constitutive germination. These data suggest that GerAB is the L-alanine sensor and that B subunits in this broadly conserved family function in nutrient detection.Competing Interest StatementThe authors have declared no competing interest.