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

Bacteria continuously adapt to changes in their environment. Responses are largely
controlled by signal transduction systems that contain two central enzymatic components, a …

Nucleic acid polymerases and helicases often contain additional domains that possess
nuclease or phosphohydrolase activity; these domains also tend to occur as 'stand …

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

The PII family of signal transduction proteins are among the most widely distributed signal
proteins in the bacterial world. First identified in 1969 as a component of the glutamine …

A detailed analysis of the polβ superfamily of nucleotidyltransferases was performed using
computer methods for iterative database search, multiple alignment, motif analysis and …

The metabolic capabilities of animals have been derived from well-studied model organisms
and are generally considered to be well understood. In animals, cysteine is an important …

Despite extensive study of individual enzymes and their organization into pathways, the
means by which enzyme networks control metabolite concentrations and fluxes in cells …

Assimilation of nitrogen requires the synthesis of only two central intermediates, glutamate
and glutamine, from which other compounds derive nitrogen by secondary transfers. We …

In continuing studies, Woolfolk developed procedures for the partial purification of GS from
crude extracts of E. coli. In studies with these enzyme preparations, he showed that whereas …