The type II secretion pathway of Pseudomonas aeruginosa is involved in the extracellular release of various toxins and hydrolytic enzymes such as exotoxin A and elastase. This pathway requires the function of a macromolecular complex called the Xcp secreton. The Xcp secreton shares many features with the machinery involved in type IV pilus assembly. More specifically, it involves the function o...

Three gonococcal genes have been identified which encode proteins with substantial similarities to known components of the type IV pilus biogenesis pathway in Pseudomonas aeruginosa. Two of the genes were identified based on their hybridization with a DNA probe derived from the pilB gene of P. aeruginosa under conditions of reduced stringency. The product of the gonococcal pilF gene is most clo...

In gram-positive bacteria, covalently linked pilus polymers are assembled by a specific transpeptidase enzyme called pilus-specific sortase. This sortase is postulated to cleave the LPXTG motif of a pilin precursor between threonine and glycine and to form an acyl enzyme intermediate with the substrate. Pilus polymerization is believed to occur through the resolution of this intermediate upon s...

Adhesive P pili of uropathogenic Escherichia coli were not assembled by a strain that lacks the periplasmic disulfide isomerase DsbA. This defect was mostly attributed to the immunoglobulin-like pilus chaperone PapD, which possesses an unusual intrasheet disulfide bond between the last two beta-strands of its CD4-like carboxyl-terminal domain. The DsbA-dependent formation of this disulfide bond...

Glycosylation is a posttranslational modification utilized in all three domains of life. Compared to eukaryotic and bacterial systems, knowledge of the archaeal processes involved in glycosylation is limited. Recently, Methanococcus voltae flagellin proteins were found to have an N-linked trisaccharide necessary for proper flagellum assembly. Current analysis by mass spectrometry of Methanococc...

The signaling molecule cyclic diguanylate (c-di-GMP) mediates physiological adaptation to extracellular stimuli in a wide range of bacteria. The complex metabolic pathways governing c-di-GMP synthesis and degradation are highly regulated, but the specific cues that impact c-di-GMP signaling are largely unknown. In the intestinal pathogen Clostridium difficile, c-di-GMP inhibits flagellar motili...

Pseudomonas syringae pathovar tabaci 11528 (P. syringae 11528) is a phytopathogen that causes wild-fire disease in soybean and tobacco plants. It utilizes a cell density-dependent regulation system known as quorum sensing (QS). In its QS system, the psyI is responsible for the biosynthesis of N-acylhomoserine lactones (AHLs). By comparing the transcripts from P. syringae 11528 wild-type strain ...

ToxR is a bitopic membrane protein that controls virulence gene expression in Vibrio cholerae. Its cytoplasmic domain is homologous to the winged helix-turn-helix ('winged helix') DNA-binding/transcription activation domain found in a variety of prokaryotic and eukaryotic regulators, whereas its periplasmic domain is of ill-defined function. Several genes in V. cholerae are regulated by ToxR, b...

This study investigated the role of three genes comprising part of the operon which encodes CS5 pili from enterotoxigenic Escherichia coli. In-frame gene deletions were constructed, and the effects on biogenesis of the pili were examined. A deletion in csfB abolished CsfA major subunit accumulation in the periplasm, which could be restored by trans-complementation with a complete copy of the cs...

Streptococcus pneumoniae is the leading cause of vaccine-preventable deaths globally. The objective of this study was to determine the distribution and clonal type variability of three potential vaccine antigens: Pneumococcal serine-rich repeat protein (PsrP), Pilus-1, and Pneumococcal choline binding protein A (PcpA) among pneumococcal isolates from children with invasive pneumococcal disease ...