Related Experiment Videos
Expression, secretion, and processing of staphylococcal nuclease by Corynebacterium glutamicum
W Liebl1, A J Sinskey, K H Schleifer
1Lehrstuhl für Mikrobiologie, Technische Universität München, Germany.
Journal of Bacteriology
|March 1, 1992
Summary
The staphylococcal nuclease (SNase) gene was successfully expressed and secreted in Corynebacterium glutamicum, with processing similar to Staphylococcus aureus. Salt concentration influenced SNase location and processing in the recombinant host.
Area of Science:
- Molecular biology
- Biotechnology
- Enzyme engineering
Background:
- Staphylococcal nuclease (SNase) is an extracellular enzyme from Staphylococcus aureus.
- Understanding heterologous gene expression and protein secretion in industrial microorganisms like Corynebacterium glutamicum is crucial for biotechnology.
- Investigating protein processing and export mechanisms in different Gram-positive hosts provides insights into cellular machinery.
Purpose of the Study:
- To express the staphylococcal nuclease (SNase) gene in Corynebacterium glutamicum.
- To analyze the secretion, processing, and location of SNase in the heterologous host.
- To investigate the influence of environmental factors, such as salt concentration, on SNase production and processing.
Main Methods:
- Gene introduction and expression of staphylococcal nuclease (SNase) in Corynebacterium glutamicum.
- Amino-terminal sequencing to determine signal peptide cleavage site.
- Analysis of SNase location (cell-associated vs. supernatant) under varying salt concentrations.
- Construction of an Escherichia coli-C. glutamicum shuttle vector for inducible gene expression.
Main Results:
- Successful expression and efficient secretion of SNase into the culture medium of C. glutamicum.
- Signal peptide cleavage occurred at the same position as in Staphylococcus aureus.
- A smaller, processed form (A form) of SNase was detected, similar to S. aureus.
- Sodium chloride concentration significantly affected SNase location and processing, with high salt promoting secretion and inhibiting processing to the A form.
- IPTG-inducible overexpression and secretion of SNase were achieved using a novel shuttle vector.
Conclusions:
- Corynebacterium glutamicum can efficiently express and secrete staphylococcal nuclease (SNase) with correct signal peptide processing.
- Salt concentration is a critical factor regulating SNase export and maturation in C. glutamicum.
- The developed expression system enables inducible SNase production in C. glutamicum, facilitating further studies and applications.