Nitrogen metabolism in prokaryotes involves the coordinated expression of a large number
of enzymes concerned with both utilization of extracellular nitrogen sources and intracellular …

We present a comprehensive overview of the hierarchical network of intracellular processes
revolving around central nitrogen metabolism in Escherichia coli. The hierarchy intertwines …

DNA looping is generated by a protein or complex of proteins that simultaneously binds to
two different sites on a DNA molecule. Consequently, the intervening tens to thousands of …

When the Going Gets Tough, the Tough Get Going Life in the microbial world is no picnic.
Hard molecular rain falls incessantly from all sides, nutrients are scarce and unpredictable …

Expression of the yellow (y) gene of Drosophila melanogaster is controlled by a series of
tissue-specific transcriptional enhancers located in the 5'region and intron of the gene …

Because of theirability to stimulate gene expression from distant sites and regardless of their
orientation, transcriptional enhancer elements are a puzzling class of regulatory DNA …

DNA-looping mechanisms are part of networks that regulate all aspects of DNA metabolism,
including transcription, replication, and recombination. DNA looping is involved in regulation …

The early notion of DNA as a passive target for regulatory proteins has given way to the
realization that higher-order DNA structures and DNA-protein complexes are at the basis of …

Mutations in the suppressor of Hairy‐wing [su (Hw)] locus reverse the phenotype of a
number of tissue‐specific mutations caused by insertion of a gypsy retrotransposon. The su …

The regulatory protein NIFA activates transcription of nitrogen fixation (nit) operons by the~
54 holoenzyme form of RNA polymerase. NIFA from Klebsiella pneumoniae activates …