Two small, multicopy, expression plasmids were constructed that permit convenient Insert ion of trpR. the structural gene for the t r £ repressor of Escherichja c o l l . with I t s natural rlbosome binding s i te or adjacent to the Mbosome bindTn? s i te for the t r £ leader peptide. In these plasmids trpR 1s positioned between the strong regulated ta£ promoter and the rpoC transcr ipt ion ter...

In Escherichia & (and other bacteria), antibiotic resistance can be acquired by chromosomal mutations, often in genes coding for ribosomal proteins. Mutations can also generate organisms that now require an antibiotic for growth. For example, streptomycin resistance or dependence both result from single amino acid changes in ribosomal protein S12 113. However, other examples of antibiotic depen...

Signal coordinating a response by multiple RNAP holoenzymes. In Escherichia coli, the vast majority of transcription results from the RNA polymerase (RNAP) holoenzyme containing 70 (E ). However, there are six other factors that each recognize other sets of promoters, often united by common function. 32 ( ) controls heat shock promoters, 54 ( ) controls promoters for nitrogen assimilation (as w...

18 Plant-derived aromatic compounds are important components of the dissolved organic carbon 19 pool in coastal salt marshes, and their mineralization by resident bacteria contributes to carbon 20 cycling in these systems. Members of the roseobacter lineage of marine bacteria are abundant in 21 coastal salt marshes and several characterized strains, including Sagittula stellata E-37, utilize 22...

Transcript elongation and termination in Escherichia coli is modulated, in part, by the nusA gene product, an acidic protein that interacts not only with RNA polymerase itself but also with ancillary factors, namely the host termination protein Rho and phage X antitermination protein, N. The E. coli nusAl mutant fails to support X development due to a specific defect in N-mediated antiterminati...