LytM factors affect the recruitment of autolysins to the cell division site in Caulobacter crescentus.

Most bacteria possess a peptidoglycan cell wall that determines their morphology and provides mechanical robustness during osmotic challenges. The biosynthesis of this structure is achieved by a large set of synthetic and lytic enzymes with varying substrate specificities. Although the biochemical functions of these proteins are conserved and well-investigated, the precise roles of individual factors and the regulatory mechanisms coordinating their activities in time and space remain incompletely understood.

A D, D-carboxypeptidase is required for Vibrio cholerae halotolerance.

The biological roles of low molecular weight penicillin-binding proteins (LMW PBP) have been difficult to discern in Gram-negative organisms. In Escherichia coli, mutants lacking these proteins often have no phenotype, and cells lacking all seven LMW PBPs remain viable. In contrast, we report here that Vibrio cholerae lacking DacA-1, a PBP5 homologue, displays slow growth, aberrant morphology and altered peptidoglycan (PG) homeostasis in Luria-Bertani (LB) medium, as well as a profound plating defect.

Molecular toolbox for genetic manipulation of the stalked budding bacterium Hyphomonas neptunium.

The alphaproteobacterium Hyphomonas neptunium proliferates by a unique budding mechanism in which daughter cells emerge from the end of a stalk-like extension emanating from the mother cell body. Studies of this species so far have been hampered by the lack of a genetic system and of molecular tools allowing the regulated expression of target genes. Based on microarray analyses, this work identifies two H.

Cell separation in Vibrio cholerae is mediated by a single amidase whose action is modulated by two nonredundant activators.

Synthesis and hydrolysis of septal peptidoglycan (PG) are critical processes at the conclusion of cell division that enable separation of daughter cells. Cleavage of septal PG is mediated by PG amidases, hydrolytic enzymes that release peptide side chains from the glycan strand. Most gammaproteobacteria, including Escherichia coli, encode several functionally redundant periplasmic amidases.

Differential requirement for PBP1a and PBP1b in in vivo and in vitro fitness of Vibrio cholerae.

We investigated the roles of the Vibrio cholerae high-molecular-weight bifunctional penicillin binding proteins, PBP1a and PBP1b, in the fitness of this enteric pathogen. Using a screen for synthetic lethality, we found that the V. cholerae PBP1a and PBP1b proteins, like their Escherichia coli homologues, are each essential in the absence of the other and in the absence of the other's putative activator, the outer membrane lipoproteins LpoA and LpoB, respectively.

Function and localization dynamics of bifunctional penicillin-binding proteins in Caulobacter crescentus.

The peptidoglycan cell wall of bacteria is a complex macromolecule composed of glycan strands that are cross-linked by short peptide bridges. Its biosynthesis involves a conserved group of enzymes, the bifunctional penicillin-binding proteins (bPBPs), which contain both a transglycosylase and a transpeptidase domain, thus being able to elongate the glycan strands and, at the same time, generate the peptide cross-links. The stalked model bacterium Caulobacter crescentus possesses five bPBP paralogs, named Pbp1A, PbpC, PbpX, PbpY, and PbpZ, whose function is still incompletely understood.

A multidomain hub anchors the chromosome segregation and chemotactic machinery to the bacterial pole.

The cell poles constitute key subcellular domains that are often critical for motility, chemotaxis, and chromosome segregation in rod-shaped bacteria. However, in nearly all rods, the processes that underlie the formation, recognition, and perpetuation of the polar domains are largely unknown. Here, in Vibrio cholerae, we identified HubP (hub of the pole), a polar transmembrane protein conserved in all vibrios, that anchors three ParA-like ATPases to the cell poles and, through them, controls polar localization of the chromosome origin, the chemotactic machinery, and the flagellum.

Influence of satiety and subjective valence rating on cerebral activation patterns in response to visual stimulation with high-calorie stimuli among restrictive anorectic and control women.

Background: There is evidence that patients with anorexia nervosa (AN) demonstrate specific cerebral activation patterns in response to visual food stimulation. We postulated that cerebral activation patterns could represent different perceptions of high-calorie images during hunger and satiety and could be determined by patients' subjective ratings.

Methods: After 6 h of starvation and also in a state of satiety, 12 female patients with AN and 12 normal-weight women were assessed by use of fMRI with high-calorie food images.

DipM, a new factor required for peptidoglycan remodelling during cell division in Caulobacter crescentus.

In bacteria, cytokinesis is dependent on lytic enzymes that facilitate remodelling of the cell wall during constriction. In this work, we identify a thus far uncharacterized periplasmic protein, DipM, that is required for cell division and polarity in Caulobacter crescentus. DipM is composed of four peptidoglycan binding (LysM) domains and a C-terminal lysostaphin-like (LytM) peptidase domain.

FtsN-like proteins are conserved components of the cell division machinery in proteobacteria.

In bacteria, cytokinesis is mediated by a ring-shaped multiprotein complex, called divisome. While some of its components are widely conserved, others are restricted to certain bacterial lineages. FtsN is the last essential cell division protein to localize to the division septum in Escherichia coli and is poorly conserved outside the enteric bacteria.

[Distortion of hunger and satiation in patients with restrictive anorexia nervosa].

The controlled study examined the distortion of hunger und satiation in 12 patients with restrictive AN (BMI = 14.0; SD: 1.78; age 27.