Modulation of Gene Expression Made Easy

• DOI: 10.1128/aem.68.5.2397-2403.2002
• Publication Date: 2002-07-27T10:09:29Z
• Authors: Christian Solem; Peter Ruhdal Jensen
• Keywords: 0301 basic medicine; L-Lactate Dehydrogenase; Pyruvate Kinase; Drug Resistance; Gene Expression Regulation, Bacterial; Chromosomes, Bacterial; Lactococcus lactis; 03 medical and health sciences; Phosphofructokinases; Operon; Promoter Regions, Genetic; Biotechnology

ABSTRACT A new approach for modulating gene expression, based on randomization of promoter (spacer) sequences, was developed. The method applied to chromosomal genes in Lactococcus lactis and shown generate libraries clones with broad ranges expression levels target genes. In one example, overexpression achieved by introducing an additional copy into a phage attachment site the chromosome. This resulted series strains phosphofructokinase activities from 1.4 11 times wild-type activity level. this pfk cloned upstream gusA encoding β-glucuronidase, resulting operon structure which both are transcribed common promoter. We show that there is linear correlation between expressions two genes, facilitates screening mutants suitable enzyme activities. second we can be native constructed las operon, containing , pyk ldh modulated integrating truncated gene. Importantly, modulation affected all three enzymes same extent, ranging 0.5 3.5 level were obtained.