Read by QxMD icon Read


Jens Hausner, Nadine Hartmann, Michael Jordan, Daniela Büttner
Pathogenicity of the Gram-negative plant-pathogenic bacterium Xanthomonas campestris pv. vesicatoria depends on a type III secretion (T3S) system, which spans both bacterial membranes and translocates effector proteins into plant cells. The assembly of the T3S system presumably involves the predicted lytic transglycosylase (LT) HpaH, which is encoded adjacent to the T3S gene cluster. Bacterial LTs degrade peptidoglycan and often promote the formation of membrane-spanning macromolecular protein complexes. In the present study, we show that HpaH localizes to the bacterial periplasm and binds to peptidoglycan as well as to components of the T3S system including the predicted periplasmic inner rod proteins HrpB1 and HrpB2 as well as the pilus protein HrpE...
November 28, 2016: Infection and Immunity
Hanchao Zhao, Susan Martinis
Aminoacyl-tRNA synthetases (AARS) comprise an enzyme family that generates and maintains pools of aminoacylated tRNAs, which serve as essential substrates for protein synthesis. Many protein synthesis factors, including tRNA and AARS also have non-canonical functions. Particularly in mammalian cells, alternate functions of AARSs have been associated with re-distribution in the cell to sites that are removed from translation. Sub-fractionation methods for E. coli were designed and optimized to carefully investigate re-localization of bacterial AARSs and tRNA that might aid in conferring alternate activities...
November 22, 2016: Methods: a Companion to Methods in Enzymology
Marie-Françoise Aries, Hélène Hernandez-Pigeon, Clémence Vaissière, Hélène Delga, Antony Caruana, Marguerite Lévêque, Muriel Bourrain, Katia Ravard Helffer, Bertrand Chol, Thien Nguyen, Sandrine Bessou-Touya, Nathalie Castex-Rizzi
BACKGROUND: Atopic dermatitis (AD) is a common skin disease characterized by recurrent pruritic inflammatory skin lesions resulting from structural and immune defects of the skin barrier. Previous studies have shown the clinical efficacy of Avène thermal spring water in AD, and a new microorganism, Aquaphilus dolomiae was suspected to contribute to these unique properties. The present study evaluated the anti-inflammatory, antipruritic, and immunomodulatory properties of ES0, an original biological extract of A...
2016: Clinical, Cosmetic and Investigational Dermatology
Jaya Sharma, Kashif Shamim, Santosh Kumar Dubey, Ram Murti Meena
Lead resistant Providencia vermicola strain SJ2A was isolated from the waste of a battery manufacturing industry which could tolerate upto 3.0mM lead nitrate in the minimal medium. Interestingly, this isolate showed presence of a plasmid borne metallothionein gene, bmtA that matched significantly (96%) with that of Pseudomonas aeruginosa. Scanning electron micrographs of bacterial cells exposed to lead revealed a unique alteration in the cell morphology from rods to long inter-connected filaments. On the other hand, electron dispersive X-ray spectroscopy (EDX) clearly indicated no significant lead adsorption therefore, we speculated intracellular sequestration in this bacterial strain...
November 19, 2016: Science of the Total Environment
Viktoria Bågenholm, Sumitha K Reddy, Hanene Bouraoui, Johan Morrill, Evelina Kulcinskaja, Constance M Bahr, Oskar Aurelius, Theresa Rogers, Yao Xiao, Derek T Logan, Eric C Martens, Nicole M Koropatkin, Henrik Stålbrand
A recently identified polysaccharide utilisation locus (PUL) from Bacteroides ovatus ATCC8483 is transcriptionally upregulated during growth on galacto- and glucomannans. It encodes two putative glycoside hydrolase family 26 (GH26) β-mannanases, BoMan26A and BoMan26B, and a GH36 α-galactosidase, BoGal36A. The PUL also includes two glycan binding proteins, confirmed by β-mannan affinity electrophoresis. When this PUL was deleted, B. ovatus was no longer able to grow on locust bean galactomannan. BoMan26A primarily formed mannobiose from mannan polysaccharides...
November 21, 2016: Journal of Biological Chemistry
Shin-Ichiro Narita, Hajime Tokuda
Bacterial lipoproteins are a subset of membrane proteins localized on either leaflet of the lipid bilayer. These proteins are anchored to membranes through their N-terminal lipid moiety attached to a conserved Cys. Since the protein moiety of most lipoproteins is hydrophilic, they are expected to play various roles in a hydrophilic environment outside the cytoplasmic membrane. Gram-negative bacteria such as Escherichia coli possess an outer membrane, to which most lipoproteins are sorted. The Lol pathway plays a central role in the sorting of lipoproteins to the outer membrane after lipoprotein precursors are processed to mature forms in the cytoplasmic membrane...
November 19, 2016: Biochimica et Biophysica Acta
Firdaus Samsudin, Maite L Ortiz-Suarez, Thomas J Piggot, Peter J Bond, Syma Khalid
The envelope of Gram-negative bacteria is highly complex, containing separate outer and inner membranes and an intervening periplasmic space encompassing a peptidoglycan (PGN) cell wall. The PGN scaffold is anchored non-covalently to the outer membrane via globular OmpA-like domains of various proteins. We report atomically detailed simulations of PGN bound to OmpA in three different states, including the isolated C-terminal domain (CTD), the full-length monomer, or the complete full-length dimeric form. Comparative analysis of dynamics of OmpA CTD from different bacteria helped to identify a conserved PGN-binding mode...
November 8, 2016: Structure
Subrata Paul, Sambuddha Banerjee, Hans J Vogel
The HisJ protein from Escherichia coli and related Gram negative bacteria is the periplasmic component of a bacterial ATP-cassette (ABC) transporter system. Together these proteins form a transmembrane complex that can take up L-histidine from the environment and translocate it into the cytosol. We have studied the specificity of HisJ for binding L-His and many related naturally occurring compounds. Our data confirm that L-His is the preferred ligand, but that 1-methyl-L-His and 3-methyl-L-His can also bind, while the dipeptide carnosine binds weakly and D-histidine and the histidine degradation products, histamine, urocanic acid and imidazole do not bind...
November 12, 2016: Protein Science: a Publication of the Protein Society
Jia-Yun Yao, Yang Xu, Xue-Mei Yuan, Wen-Lin Yin, Gui-Lian Yang, Ling-Yun Lin, Xiao-Yi Pan, Chun-Feng Wang, Jin-Yu Shen
Ichthyophthirius is a severe disease of farmed freshwater fish caused by the parasitic ciliate Ichthyophthirius multifiliis (Ich). This disease can lead to considerable economic loss, but the protein profiles in different developmental stages of the parasite remain unknown. In the present study, proteins from trophonts and theronts of Ich were identified by isobaric tags for relative and absolute quantitation (iTRAQ). A total of 2300 proteins were identified in the two developmental stages, of which 1520 proteins were differentially expressed...
November 18, 2016: Parasitology Research
Lin Zhang, Christian Trncik, Susana L A Andrade, Oliver Einsle
The copper-containing enzyme nitrous oxide reductase (N2OR) catalyzes the transformation of nitrous oxide (N2O) to dinitrogen (N2) in microbial denitrification. Several accessory factors are essential for assembling the two copper sites CuA and CuZ and for maintaining their activity. In particular, the deletion of either the transmembrane iron-sulfur flavoprotein NosR or the periplasmic protein NosX, a member of the ApbE family, abolishes N2O respiration. Here we demonstrate through biochemical and structural studies that the ApbE protein from Pseudomonas stutzeri, where the nosX gene is absent, is a monomeric FAD-binding protein that can serve as the flavin donor for NosR maturation via covalent flavinylation of a threonine residue...
November 15, 2016: Biochimica et Biophysica Acta
Monika Żelazowska, Dorota Fopp-Bayat
Previtellogenic and vitellogenic oocytes in ovarian follicles from cultured Siberian sturgeon Acipenser baerii were examined. In previtellogenic oocytes, granular and homogeneous zones in the cytoplasm (the ooplasm) are distinguished. Material of nuclear origin, rough endoplasmic reticulum, Golgi complexes, complexes of mitochondria with cement and round bodies are numerous in the granular ooplasm. In vitellogenic oocytes, the ooplasm comprises three zones: perinuclear area, endoplasm and periplasm. The endoplasm contains yolk platelets, lipid droplets, and aggregations of mitochondria and granules immersed in amorphous material...
November 8, 2016: Journal of Morphology
Padmani Sandhu, Monika Kumari, Kamal Naini, Yusuf Akhter
Periplasmic-binding proteins occupy the periplasmic space of bacteria and are involved in binding and transport of various ions, siderophores, and other diverse types of solutes. These proteins may be associated with membrane transport systems or may help in activation of signal transducers. There is limited information available on Mycobacterium tuberculosis (Mtb) periplasm-inhabiting proteins. In the present study, we have performed genome-wide identification and functional annotation of periplasmic-binding proteins of Mtb on the basis of signature characteristics and their functional motifs...
November 17, 2016: Current Genetics
Patrick A McLaughlin, Michael McClelland, Hee-Jeong Yang, Steffen Porwollik, Lydia Bogomolnaya, Juei-Suei Chen, Helene Andrews-Polymenis, Adrianus W M van der Velden
Salmonellae are pathogenic bacteria that cause significant morbidity and mortality in humans worldwide. Salmonellae establish infection and avoid clearance by the immune system by mechanisms that are not well understood. We previously showed that L-Asparaginase II produced by Salmonella enterica serovar Typhimurium (S Typhimurium) inhibits T cell responses and mediates virulence. In addition, we previously showed that asparagine deprivation such as that mediated by L-Asparaginase II of S Typhimurium causes suppression of activation-induced T cell metabolic reprogramming...
November 14, 2016: Infection and Immunity
Zhuan Qin, Wei-Ting Lin, Shiwei Zhu, Aime T Franco, Jun Liu
: Helicobacter pylori is a bacterial pathogen that can cause many gastrointestinal diseases including ulcers and gastric cancer. A unique chemotaxis-mediated motility is critical for H. pylori to colonize in the human stomach and to establish chronic infection, but the underlying molecular mechanisms are not well understood. Here we employ cryo-electron tomography to reveal detailed structures of the H. pylori cell envelope including the sheathed flagella and chemotaxis arrays. Notably, H...
November 14, 2016: Journal of Bacteriology
Behnam Tabatabai, AnithaChristy S Arumanayagam, Oluwatomisin Enitan, Arunmani Mani, Savithiry S Natarajan, Viji Sitther
Energy metabolism and photosynthetic pigment accumulation are affected by salt stress in cyanobacteria leading to cessation of growth. In this study, the effect of salinity on the freshwater cyanobacterium, Fremyella diplosiphon, was investigated and mutagenesis-based efforts were undertaken to enhance salt tolerance. Salinity at a concentration of 10 g/L sodium chloride (NaCl) inhibited growth of wild type F. diplosiphon under white, red, and green light. Efforts to enhance halotolerance resulted in a mutant that could survive in 20 g/L NaCl for 15 generations with no significant reduction in phycobiliproteins (phycocyanin, phycoerythrin, and allophycocyanin) or chlorophyll a...
November 14, 2016: Current Microbiology
Xiaowei Zhao, Cindi Schwartz, Jason Pierson, Stephen J Giovannoni, J Richard McIntosh, Daniela Nicastro
: SAR11 bacteria are small, heterotrophic, marine α-proteobacteria found throughout the oceans. They thrive at the low nutrient concentrations typical of open ocean conditions, although the adaptations required for life under these conditions are not well understood. To illuminate this issue we used cryo-electron tomography to study Pelagibacter, strain HTCC1062, a member of SAR11 clade. Our results revealed its cellular dimensions and details of its intracellular organization. The frozen-hydrated cells, which are preserved in a life-like state, have an average cell volume (enclosed by outer membrane) of 0...
November 11, 2016: Applied and Environmental Microbiology
Youichi Naoe, Nozomi Nakamura, Akihiro Doi, Mia Sawabe, Hiro Nakamura, Yoshitsugu Shiro, Hiroshi Sugimoto
Pathogenic bacteria remove iron from the haem of host tissues and use it as a catalytic center of many enzymes. Haem uptake by pathogenic bacteria is facilitated by the membrane-integrated haem importer, which belongs to the type II ATP-binding cassette (ABC) transporter. Here we present crystal structures of Burkholderia cenocepacia haem importer BhuUV complexed with the periplasmic haem-binding protein BhuT and in the absence of BhuT. The transmembrane helices of these structures show an inward-facing conformation, in which the cytoplasmic gate of the haem translocation pathway is completely open...
November 10, 2016: Nature Communications
Yajie Wang, M Fata Moradali, Ali Goudarztalejerdi, Ian M Sims, Bernd H A Rehm
Carbohydrate polymers are industrially and medically important. For instance, a polysaccharide, alginate (from seaweed), is widely used in food, textile and pharmaceutical industries. Certain bacteria also produce alginate through membrane spanning multi-protein complexes. Using Pseudomonas aeruginosa as a model organism, we investigated the biological function of an alginate degrading enzyme, AlgL, in alginate production and biofilm formation. We showed that AlgL negatively impacts alginate production through its enzymatic activity...
November 8, 2016: Scientific Reports
Anas Allam, Laure Maigre, Rodolphe Alves de Sousa, Estelle Dumont, Julia Vergalli, Jean-Marie Pagès, Isabelle Artaud
Structure of bacterial envelope is one of the major factors contributing to Gram negative bacterial resistance. To develop new agents that target the bacterial membranes, we synthesized, by analogy with our previous peptide conjugates, new amphiphilic 3',4',6-trinaphthylmethylene neamines functionalized at position 5 through a short spacer by a chelating group, tris(2-pyridylmethyl)amine (TPA) and di-(picolyl)amine (DPA) and tetraazacyclotetradecane (Cyclam). ESI(+) mass spectrometry analyses showed that neither Zn(II)(NeaDPA) nor Cu(II)(NeaCyclam) were stable in the Mueller Hinton (MH) medium used for antibacterial assays...
October 25, 2016: European Journal of Medicinal Chemistry
Meztlli O Gaytán, Verónica I Martínez-Santos, Eduardo Soto, Bertha González-Pedrajo
Enteropathogenic Escherichia coli and enterohemorrhagic E. coli are diarrheagenic bacterial human pathogens that cause severe gastroenteritis. These enteric pathotypes, together with the mouse pathogen Citrobacter rodentium, belong to the family of attaching and effacing pathogens that form a distinctive histological lesion in the intestinal epithelium. The virulence of these bacteria depends on a type III secretion system (T3SS), which mediates the translocation of effector proteins from the bacterial cytosol into the infected cells...
2016: Frontiers in Cellular and Infection Microbiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"