ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary The Clostridium thermocellum cellulase genes celA and celC encoding endoglucanase A and C were subcloned in a temperature-regulated Escherichia coli expression vector containing the leftward promoterpl of bacteriophage lambda. The level of gene expression was controlled by thermal inactivation of the heat-sensitive lambda cI857 repressor. Under optimal conditions the recombinant endoglucanases A and C were expressed to a level of 10–15% of total cellular protein. Endoglucanase A was partially exported into the periplasmic space, whereas endoglucanase C was found sequestered within the cytoplasm. Overexpression of the celA gene resulted in decreased cell viability concomitant with the accumulation of endoglucanase A in the membrane fraction. In contrast, high-level synthesis of the celC gene product was well tolerated by the host cell. Overproduced endoglucanase C accumulated as a soluble enzyme without detectable formation of inactive inclusion bodies.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00257253
