Asporogenic Bacillus megaterium mutant 27-36 degrades intrinsically short-lived proteins but fails to convert most of other proteins to a short-lived fraction.
Asporogenic mutant blocked in the 0-II sporulation stage degraded pulse-labelled proteins in the sporulation medium at the same rate as the parental strain for the first two hours. The degraded fraction was mostly composed of intrinsically short-lived proteins which were degraded even after enriching the medium with amino acids and growth resumption. Proteins accessible to degradation because of nutritional shift down formed a lesser proportion of this fraction. The acceleration of protein turnover in the parent strain during the irreversible sporulation phase was not developed in the mutant. A first order kinetic model of protein degradation was used for parameter estimation. Ca(2+)-dependent intracellular serine proteinase was synthesized in an inactive form, which was activated by increasing Ca2+ concentration to 30 mM.
Chaloupka
J
J
Institute of Microbiology, Academy of Sciences of the Czech Republic, Praha.
Kucerová
H
H
Strnadová
M
M
Votruba
J
J
Ludvík
J
J
D001410:Bacillus megaterium / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D007700:Kinetics; D009154:Mutation; D012697:Serine Endopeptidases / Q000378:metabolism; D013171:Spores, Bacterial / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D012697:Serine Endopeptidases; D002118:Calcium