Theallostericmechanismbywhich the gene expression regulatory protein AraC regulates its DNA-binding activity is shown to be portable by grafting it to -galactosidase, generating an arabinose-regulated -galactosidase. A portion of the -peptide sequence that complements the activity of -acceptor -galactosidase was inserted into a nonessential region of the regulatory peptidyl arm of AraC protein....

This review covers the physiological aspects of regulation of the arabinose operon in Escherichia coli and the physical and regulatory properties of the operon's controlling gene, araC. It also describes the light switch mechanism as an explanation for many of the protein's properties. Although many thousands of homologs of AraC exist and regulate many diverse operons in response to many differ...

Bacillus subtilis 168 is unable to grow on xylose and galactose as sole carbon sources, owing to the lack of specific transporters. We show that they are imported into the cell by the activity of AraE, an arabinose transporter whose synthesis is induced by L-arabinose.

The Escherichia coli araBAD operon consists of three genes encoding three enzymes that convert L-arabinose to D-xylulose-5 phosphate. In this paper we report that the genes of the E. coli araBAD operon have been expressed in Saccharomyces cerevisiae using strong promoters from genes encoding S. cerevisiae glycolytic enzymes (pyruvate kinase, phosphoglucose isomerase, and phosphoglycerol kinase)...

The chvE-gguABC operon plays a critical role in both virulence and sugar utilization through the activities of the periplasmic ChvE protein, which binds to a variety of sugars. The roles of the GguA, GguB, and GguC are not known. While GguA and GguB are homologous to bacterial ABC transporters, earlier genetic analysis indicated that they were not necessary for utilization of sugars as the sole...

The L-arabinose-binding protein (ABP) of Escherichia coli consists structurally of two distinct globular domains connected by a hinge of three separate peptide segments. Arabinose is bound and completely sequestered within the deep cleft between the two domains. With reduced affinity, ABP also binds D-galactose (approximately 2-fold reduction) and D-fucose (approximately 40-fold reduction). Exp...

The arabinose-binding pockets of wild type AraC dimerization domains crystallized in the absence of arabinose are occupied with the side chains of Y31 from neighboring domains. This interaction leads to aggregation at high solution concentrations and prevents determination of the structure of truely apo AraC. In this work we found that the aggregation does not significantly occur at physiologic...

We have devised and constructed a biological containment system designed to cause programmed bacterial cell lysis with no survivors. We have validated this system, using Salmonella enterica serovar Typhimurium vaccines for antigen delivery after colonization of host lymphoid tissues. The system is composed of two parts. The first component is Salmonella typhimurium strain chi8937, with deletion...

In this study, we determine concentrations of neutral and amino sugars and a sugar alcohol in freshwaters using high-performance liquid chromatography and pulsed amperometric detection with a single isocratic analysis. Coeluting arabinose, galactosamine, and mannosamine are separated with a mobile phase of 22.8 mM NaOH-KOH at a temperature of 17 degrees C. The resolutions are 0.73 and 0.64, res...

In the accompanying paper [Beylot, McKie, Voragen, Doeswijk-Voragen and Gilbert (2001) Biochem. J. 358, 607-614] the chromosome of Pseudomonas cellulosa was shown to contain two genes, abf51A and abf62A, that encode arabinofuranosidases belonging to glycoside hydrolase families 51 and 62, respectively. In this report we show that expression of Abf51A is induced by arabinose and arabinose-contai...