Increased Proteolytic Activity of Clinical Isolate HU1848 Is Associated with Higher Expression.

is a global opportunistic pathogen. cytotoxicity of this bacterium is mainly related to metalloprotease serralysin (PrtS) activity. Proteolytic capability varies among the different isolates.

antibiotic resistance mechanisms of an opportunistic pathogen: a literature review.

is a ubiquitous bacterium from order displaying a high genetic plasticity that allows it to adapt and persist in multiple niches including soil, water, plants, and nosocomial environments. Recently, has gained attention as an emerging pathogen worldwide, provoking infections and outbreaks in debilitated individuals, particularly newborns and patients in intensive care units. isolates recovered from clinical settings are frequently described as multidrug resistant.

Dissemination of Gram-positive bacteria to the lung of newborn mice increases local IL-6 and TNFα levels in lethal bacteremia.

Neonatal bacteremia remains the major cause of infectious diseases-related death, especially in preterm newborns. Gram-positive bacteria are the main causative agent of neonatal bacteremia and exhibit a high risk of causing pneumonia and/or meningitis. The pathogenesis of bacteremia in preterm newborn is poorly understood.

Defining chaperone-usher fimbriae repertoire in Serratia marcescens.

Chaperone-usher (CU) fimbriae are surface organelles particularly prevalent among the Enterobacteriaceae. Mainly associated to their adhesive properties, CU fimbriae play key roles in biofilm formation and host cell interactions. Little is known about the fimbriome composition of the opportunistic human pathogen Serratia marcescens.

In vitro anticancer activity of methanolic extract of sp., a microalgae from an oligotrophic oasis in the Chihuahuan desert.

With the purpose of discovering new anticancer molecules that might have fewer side effects or reduce resistance to current antitumor drugs, a bioprospecting study of the microalgae of the Cuatro Cienegas Basin (CCB), an oasis in the Chihuahuan desert in Mexico was conducted. A microalgae was identified as sp. through sequencing the gene and reconstruction of a phylogenetic tree, and its anticancer activities were assessed using various in vitro assays and different cell lines of human cancers, including lung, skin melanoma, colorectal, breast and prostatic cancers, as well as a normal cell line.

Sulfhydryl Labeling as a Tool to Investigate the Topology of Membrane Proteins Involved in Lipopolysaccharide Biosynthesis.

Establishing the topology of membrane proteins, especially when their tridimensional structures are unavailable, is critical to identify functional regions, delimit the protein orientation in the membrane, the number of transmembrane segments, and the position of critical amino acids (whether exposed to the solvent or embedded in the lipid bilayer). Elucidating the topology of bacterial integral membrane proteins typically involves the construction of deletion-fusions whereby regions of the protein are fused to reporters. Although these methods have several advantages, they are also artifact prone.

Anticancer potential of Thevetia peruviana fruit methanolic extract.

Background: Thevetia peruviana (Pers.) K. Schum or Cascabela peruviana (L.

Tyrosine Phosphorylation and Dephosphorylation in Burkholderia cenocepacia Affect Biofilm Formation, Growth under Nutritional Deprivation, and Pathogenicity.

Burkholderia cenocepacia, a member of the B. cepacia complex (Bcc), is an opportunistic pathogen causing serious chronic infections in patients with cystic fibrosis. Tyrosine phosphorylation has emerged as an important posttranslational modification modulating the physiology and pathogenicity of Bcc bacteria.

ArnT proteins that catalyze the glycosylation of lipopolysaccharide share common features with bacterial N-oligosaccharyltransferases.

ArnT is a glycosyltransferase that catalyzes the addition of 4-amino-4-deoxy-l-arabinose (l-Ara4N) to the lipid A moiety of the lipopolysaccharide. This is a critical modification enabling bacteria to resist killing by antimicrobial peptides. ArnT is an integral inner membrane protein consisting of 13 predicted transmembrane helices and a large periplasmic C-terminal domain.

Burkholderia cenocepacia and Salmonella enterica ArnT proteins that transfer 4-amino-4-deoxy-l-arabinose to lipopolysaccharide share membrane topology and functional amino acids.

We recently demonstrated that incorporation of 4-amino-4-deoxy-l-arabinose (l-Ara4N) to the lipid A moiety of lipopolysaccharide (LPS) is required for transport of LPS to the outer membrane and viability of the Gram-negative bacterium Burkholderia cenocepacia. ArnT is a membrane protein catalyzing the transfer of l-Ara4N to the LPS molecule at the periplasmic face of the inner membrane, but its topology and mechanism of action are not well characterized. Here, we elucidate the topology of ArnT and identify key amino acids that likely contribute to its enzymatic function.

Protein synthesis and assembly in mitochondrial disorders.

Human mitochondrial DNA (mtDNA) codes for 13 polypeptides which constitute the central core of the oxidative phosphorylation (OXPHOS) complexes. The machinery for mitochondrial protein synthesis has a dual origin: a full set of tRNAs, as well as the 12S and 16S rRNAs are encoded in the mitochondrial genome, while most factors necessary for translation are encoded by nuclear genes. The mitochondrial translation apparatus is highly specialized in expressing membrane proteins, and couples the synthesis of proteins to the insertion into the mitochondrial inner membrane.

The pentatricopeptide repeats present in Pet309 are necessary for translation but not for stability of the mitochondrial COX1 mRNA in yeast.

Pet309 is a protein essential for respiratory growth. It is involved in translation of the yeast mitochondrial COX1 gene, which encodes subunit I of the cytochrome c oxidase. Pet309 is also involved in stabilization of the COX1 mRNA.