Protein
Stage II sporulation protein SA
Organism
Bacillus subtilis (strain 168)
Function
Toxic component of a type II toxin-antitoxin (TA) system. Its toxic activity is neutralized by cognate antitoxin SpoIISB. Expression in the absence of SpoIISB permits sporulation to stage II, when plasmolysis zones and holes in the peptidoglycan layer are observed, resulting in cell death. Lethal when synthesized during vegetative growth in the absence of SpoIISB. In E.coli both the membrane bound and soluble domain are required in cis for toxin activity.
Similarity
Belongs to the SpoIISA toxin family.
Sequence
MVLFFQIMVWCIVAGLGLYVYATWRFEAKVKEKMSAIRKTWYLLFVLGAMVYWTYEPTSLFTHWERYLIVAVSFALIDAFIFLSAYVKKLAGSELETDTREILEENNEMLHMYLNRLKTYQYLLKNEPIHVYYGSIDAYAEGIDKLLKTYADKMNLTASLCHYSTQADKDRLTEHMDDPADVQTRLDRKDVYYDQYGKVVLIPFTIETQNYVIKLTSDSIVTEFDYLLFTSLTSIYDLVLPIEEEGEG