Elevated Fis expression enhances recombinant protein production in Escherichia coli

✍ Scribed by Richard Richins; Tin Htay; Pauli Kallio; Wilfred Chen

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 134 KB
• Volume: 56
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(19971020)56:2<138::aid-bit3>3.0.co;2-q

✦ Synopsis

A genetic strategy to enhance recombinant protein production is discussed. A small DNA bending protein, Fis, which has been shown to activate rRNA synthesis upon a nutrient upshift, was overexpressed in E. coli strain W3110 carrying vector pUCR1. Overexpres- sion of Fis during exponential growth was shown to activate rrn promoters to different extents. A 5-fold improvement in chloramphenicol acetyltransferase (CAT) production in cultures with elevated Fis level was observed in shake-flask cultivations. A similar improvement in the culture performance was also observed during fedbatch fermentation; the specific CAT activity increased by more than 50% during the fed-batch phase for cultures with elevated Fis expression. In contrast, no increase in specific CAT activity was detected for cultures carrying pUCR2, expressing a frame-shift Fis mutant. Expression of Fis from a complementary vector, pKFIS, restored CAT production from W3110:pUCR2 to approximately the same level as cultures carrying pUCR1, indicating that the enhancement in CAT production was indeed Fis-dependent. The framework presented here suggests that differential activation in recombinant protein production may be achieved with differential Fis overexpression.