Abstract
The enzyme TEM beta-lactamase constitutes a versatile gene-fusion marker for studies on membrane proteins and protein export in bacteria. The mature form of this normally periplasmic enzyme displays readily detectable and distinctly different phenotypes when localized to the bacterial cytoplasm versus the periplasm, and thus provides a useful alternative to alkaline phosphatase for probing the topology of cytoplasmic membrane proteins. Cells producing translocated forms of beta-lactamase can be directly selected as ampicillin-resistant colonies, and consequently a beta-lactamase fusion approach can be used for positive selection for export signals, and for rapid assessment of whether any protein expressed in Escherichia coli inserts into the bacterial cytoplasmic membrane. The level of ampicillin resistance conferred on a cell by an extracytoplasmic beta-lactamase derivative depends on its level of expression, and therefore a beta-lactamase fusion approach can be used to directly select for increased yields of any periplasmic or membrane-bound gene products expressed in E. coli.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.