Words similar to fnr
Example sentences for: fnr
How can you use “fnr” in a sentence? Here are some example sentences to help you improve your vocabulary:
5 target sites like other Fnr-regulated class II promoters [ 16 ] . By analogy to the CAP transcription regulator [ 17 18 ] , the proposed mechanism for Fnr activation of gene expression involves its ability to promote open complex formation by RNA polymerase [ 13 16 19 ] . As suggested by the appearance of DNase I hypersensitive cleavage sites, a change in the DNA conformation occurs upon Fnr binding at the dmsA promoter [ 7 8 ] . The presence of hypersensitive DNase I cleavage sites at other FNR-regulated promoters as well as DNA bending experiments support this conclusion [ 8 20 ] . Furthermore, recent studies propose the protein-protein interaction of σ 70and Fnr at the narG and dmsA promoters [ 7 21 22 23 ] . Finally, for each of the site-directed mutations of the Fnr binding site in this study, the level of dmsA-lacZ expression was not significantly altered in an fnr deletion strain either aerobically or anaerobically, indicating that the Fnr-independent expression from the dmsA promoter was not affected by the sequence alterations (Figure 1).
Hence, a single Fnr half-site is not sufficient to allow Fnr-dependent activation of the E. coli DMSO reductase genes.
The enhanced ability of Fnr to activate dmsABC gene expression is possibly, by analogy to Crp, due to increased affinity of Fnr at the consensus versus the native non-consensus Fnr recognition sequence at dmsA . Likewise, the poor match of the Fnr site at the promoter for the fumarate reductase gene, frdA to the consensus Fnr sequence may account for the relatively weak anaerobic induction for this respiratory operon [ 14 ] .
A single base substitution in the left half-site when combined with the Fnr consensus sequence at the right half-site exhibited a 138-fold activation of dmsA-lacZ expression (Figure 1, λJA450), an induction equivalent to the wild-type dmsA promoter that has the symmetrical deviation in the right half-site (ca.
Several additional DNA sequence changes were introduced into the dmsA promoter region to alter the Fnr recognition sequence as well as to alter the spacing between the Fnr site and the RNA polymerase recognition sequences (Figure 1).
Loading...