Nematodes and bacteria are major components of the soil ecosystem. Many nematodes use bacteria for food, whereas others evolved specialized bacterial interactions ranging from mutualism to parasitism. Little is known about the biological mechanisms by which nematode-bacterial interactions are achieved, largely because in the laboratory nematodes are often cultured under artificial conditions. W...

Bacterial meningitis is a serious infection of the central nervous system (CNS) that occurs after bacteria interact with and penetrate the blood-brain barrier (BBB). The BBB is comprised of highly specialized brain microvascular endothelial cells (BMECs) that function to separate the circulation from the CNS and act as a formidable barrier for toxins and pathogens. Certain bacteria, such as Str...

Our recent studies have shown that the dendritic cell-specific ICAM nonintegrin CD209 (DC-SIGN) specifically binds to the core LPS of Escherichia coli K12 (E. coli), promoting bacterial adherence and phagocytosis. In this current study, we attempted to map the sites within the core LPS that are directly involved in LPS-DC-SIGN interaction. We took advantage of four sets of well-defined core LPS...

Many Gram-negative bacteria employ N-acyl homoserine lactones (AHLs) as signal molecules for quorum sensing. The binding of AHLs to their target LuxR-type receptor proteins can effect changes in growth, virulence, and other phenotypes. LuxR-type receptors therefore present attractive pharmaceutical targets for control of bacterial pathogenesis. Here, we present X-ray crystallographic and comput...

The specific interaction between legumes and Rhizobium-type bacteria leads to the establishment of a symbiotic relationship characterized by the formation of new differentiated organs named nodules, which provide a niche for bacterial nitrogen (N2) fixation. In the nodules, bacteria differentiate into bacteroids with the ability to fix atmospheric N2 via nitrogenase activity. As nitrogenase is ...

Primitive hematopoietic stem cells (HSCs) in the bone marrow are rare pluripotent cells with the capacity to give rise to all lineages of blood cells. During commitment, progenitor cells are composed mainly of cells with the potential for differentiation into 1 or 2 lineages. This commitment involves the acquisition of specific growth factor receptors and the loss of others. Viral and bacterial...

Bacterial luciferase catalyzes the emission of visible light from the reaction of reduced flavin, molecular oxygen, and an n-alkyl aldehyde. The mechanism of the reaction was probed by measuring the electronic effects of various substituents at the 8-position of the flavin ring system. Substituent effects were obtained for CH3-, Cl-, CH3O-, CH3S-, F-, and H- on the rate of formation and decay o...

Bacterial luciferase catalyzes the reaction of FMNH2, O2, and an aliphatic aldehyde to yield the carboxylic acid, FMN, water and blue-green light. The kinetics of the bacterial luciferase reaction were measured by stopped-flow spectrophotometry at pH 7 and 25 degrees C for the series of aldehydes from n-heptanal to n-undecanal. The rate of formation of the 4a-hydroperoxyflavin intermediate was ...

Helicobacter pylori has been recognized as a major cause of most of the diseases of the stomach. These diseases are preceded by lesions of gastritis induced by H. pylori. This long-standing infection gives us a very good model of interaction between a bacterium and its host. We will review the direct and indirect effects of H. pylori.