As mediators of adhesion, autoaggregation and bacteria-induced plasma membrane reorganization, type IV pili are at the heart of Neisseria meningitidis infection. Previous studies have proposed that two minor pilins, PilV and PilX, are displayed along the pilus structure and play a direct role in mediating these effects. In contrast with this hypothesis, combining imaging and biochemical approac...

The hyperthermophilic archaeon Sulfolobus solfataricus has been shown to exhibit a complex transcriptional response to UV irradiation involving 55 genes. Among the strongest UV-induced genes was a putative pili biogenesis operon encoding a potential secretion ATPase, two pre-pilins, a putative transmembrane protein and a protein of unknown function. Electron microscopy and image reconstruction ...

Neisseria meningitidis crosses the blood-brain barrier (BBB) following the activation of the β2-adrenergic receptor by the type IV pili (TFP). Two components of the type IV pili recruit the β2-adrenergic receptor, the major pilin PilE and the minor pilin PilV. Here, we report that a strain deleted of PilX, one of the three minor pilins, is defective in endothelial cell signaling. The signaling ...

Bacteria have evolved numerous mechanisms for cell-cell communication, many of which have important consequences for human health. Among these is conjugation, the direct transfer of DNA from one cell to another. For gram-negative bacteria, conjugation requires thin, flexible filaments (conjugative pili) that are elaborated by DNA donor cells. The structure, function, and especially the dynamics...

The opportunistic pathogen Pseudomonas aeruginosa is a leading cause of nosocomial pneumonia. Among its virulence factors, the type IV pili of P. aeruginosa strain 1244 contain a covalently linked, three-sugar glycan of previously unknown significance. The work described in this paper was carried out to determine the influence of the P. aeruginosa 1244 pilin glycan on pilus function, as well as...

Early electron microscopy and more recent studies in our laboratory of Bdellovibrio bacteriovorus cells indicated the presence of narrow fibers at the nonflagellar pole of this unusual predatory bacterium. Analysis of the B. bacteriovorus HD100 genome showed a complete set of genes potentially encoding type IV pili and an incomplete gene set for Flp pili; therefore, the role of type IV pili in ...

The binding of human secretory immunoglobulin A (SIgA), the primary immunoglobulin in the gut, to Escherichia coli is thought to be dependent on type 1 pili. Type 1 pili are filamentous bacterial surface attachment organelles comprised principally of a single protein, the product of the fimA gene. A minor component of the pilus fiber (the product of the fimH gene, termed the adhesin) mediates a...

Assembly of P pili on the surface of pyelonephritic Escherichia coli proceeds from periplasmic chaperone-subunit complexes. The outer membrane protein PapC, which has been termed a molecular usher, is thought to be the site of assembly, where the chaperone dissociates from the subunits as they are incorporated into the pilus across the outer membrane. The kinetics of assembly and the energy req...

Problem: Conjugative plasmids manipulate their bacterial hosts to express sex-pili – long, filamentous organelles whose genes are carried by the plasmids themselves. Sex-pili locate and attach to another bacterial cell for plasmid transfer. Bacteria differ in their ability to express sex-pili and hence to donate plasmids. Does this diversity in sex-pilus expression contribute to the survival of...

KEYWORDS: antibiotics´bioorganic chemistry´chaperone proteins´peptidomimetics The heavy use of antibiotics during the second half of the last century has resulted in widespread bacterial resistance. Overcoming resistance requires the development of antibiotics aimed at new targets in microorganisms. Preferably, such targets should be highly conserved in bacteria and required for pathogenesis, b...