A conserved ClpP-like protease involved in spore outgrowth in Bacillus subtilis.
Germination and outgrowth of endospores of the Gram-positive bacterium Bacillus subtilis involves the degradation and conversion to free amino acids of abundant proteins located in the spore core known as small acid-soluble proteins (SASP). This degradation is mediated primarily by the germination protease Gpr. Here we show that YmfB, a distant homologue of ClpP serine proteases that is highly conserved among endospore-forming bacteria, contributes to SASP degradation but that its function is normally masked by Gpr. Spores from a ymfB gpr double mutant were more delayed in spore outgrowth and more impaired in SASP degradation than were spores from a gpr single mutant. The activity of YmfB relied on three putative active-site residues as well as on the product of a small gene ylzJ located immediately downstream of, and overlapping with, ymfB. We propose that YmfB is an orphan ClpP protease that is dedicated to the degradation of a specialized family of small protein substrates.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA.
Bjorn A
BA
Traag
Antonia
A
Pugliese
Barbara
B
Setlow
Peter
P
Setlow
Richard
R
Losick
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D001426:Bacterial Proteins / Q000378:metabolism; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D059748:Proteolysis; D013171:Spores, Bacterial / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*
D001426:Bacterial Proteins; C030069:spore-specific proteins, Bacillus; D010450:Endopeptidases