Back to Search
Start Over
Staphylococcal SplB serine protease utilizes a novel molecular mechanism of activation.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2014 May 30; Vol. 289 (22), pp. 15544-53. Date of Electronic Publication: 2014 Apr 08. - Publication Year :
- 2014
-
Abstract
- Staphylococcal SplB protease belongs to the chymotrypsin family. Chymotrypsin zymogen is activated by proteolytic processing at the N terminus, resulting in significant structural rearrangement at the active site. Here, we demonstrate that the molecular mechanism of SplB protease activation differs significantly and we characterize the novel mechanism in detail. Using peptide and protein substrates we show that the native signal peptide, or any N-terminal extension, has an inhibitory effect on SplB. Only precise N-terminal processing releases the full proteolytic activity of the wild type analogously to chymotrypsin. However, comparison of the crystal structures of mature SplB and a zymogen mimic show no rearrangement at the active site whatsoever. Instead, only the formation of a unique hydrogen bond network, distant form the active site, by the new N-terminal glutamic acid of mature SplB is observed. The importance of this network and influence of particular hydrogen bond interactions at the N terminus on the catalytic process is demonstrated by evaluating the kinetics of a series of mutants. The results allow us to propose a consistent model where changes in the overall protein dynamics rather than structural rearrangement of the active site are involved in the activation process.<br /> (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Subjects :
- Bacterial Proteins chemistry
Bacterial Proteins genetics
Bacterial Proteins metabolism
Catalytic Domain
Chymotrypsin chemistry
Chymotrypsin genetics
Chymotrypsin metabolism
Crystallography, X-Ray
Enzyme Precursors metabolism
Hydrogen Bonding
Models, Molecular
Protein Sorting Signals physiology
Protein Structure, Tertiary
Serine Proteases genetics
Staphylococcus aureus genetics
Structure-Activity Relationship
Serine Proteases chemistry
Serine Proteases metabolism
Staphylococcus aureus enzymology
Subjects
Details
- Language :
- English
- ISSN :
- 1083-351X
- Volume :
- 289
- Issue :
- 22
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 24713703
- Full Text :
- https://doi.org/10.1074/jbc.M113.507616