Read by QxMD icon Read


Jan Löwe, Shaoda He, Sjors H W Scheres, Christos G Savva
Magnetotactic bacteria produce iron-rich magnetic nanoparticles that are enclosed by membrane invaginations to form magnetosomes so they are able to sense and act upon Earth's magnetic field. In Magnetospirillum and other magnetotactic bacteria, to combine their magnetic moments, magnetosomes align along filaments formed by a bacterial actin homolog, MamK. Here, we present the crystal structure of a nonpolymerizing mutant of MamK from Magnetospirillum magneticum AMB-1 at 1.8-Å resolution, revealing its close similarity to actin and MreB...
November 22, 2016: Proceedings of the National Academy of Sciences of the United States of America
Johan van Beilen, Christoph J Blohmke, Hendrik Folkerts, Richard de Boer, Anna Zakrzewska, Wim Kulik, Fred M Vaz, Stanley Brul, Alexander Ter Beek
Weak organic acids like sorbic and acetic acid are widely used to prevent growth of spoilage organisms such as Bacilli. To identify genes involved in weak acid stress tolerance we screened a transposon mutant library of Bacillus subtilis for sorbic acid sensitivity. Mutants of the rodZ (ymfM) gene were found to be hypersensitive to the lipophilic weak organic acid. RodZ is involved in determining the cell's rod-shape and believed to interact with the bacterial actin-like MreB cytoskeleton. Since rodZ lies upstream in the genome of the essential gene pgsA (phosphatidylglycerol phosphate synthase) we hypothesized that expression of the latter might also be affected in rodZ mutants and hence contribute to the phenotype observed...
2016: Frontiers in Microbiology
Pananghat Gayathri
Bacterial actins polymerize in the presence of nucleotide (preferably ATP), form a common arrangement of monomeric interfaces within a protofilament, and undergo ATP hydrolysis-dependent change in stability of the filament-all of which contribute to performing their respective functions. The relative stability of the filament in the ADP-bound form compared to that of ATP and the rate of addition of monomers at the two ends decide the filament dynamics. One of the major differences between eukaryotic actin and bacterial actins is the variety in protofilament arrangements and dynamics exhibited by the latter...
November 6, 2016: Current Topics in Microbiology and Immunology
Jingjing Sun, Xiaojian Gao, Jiang Qun, Xuedi Du, Keran Bi, Xiaojun Zhang, Li Lin
This study aimed to evaluate the survival and gene expression of Vibrio harveyi under starvation conditions. The microcosms V. harveyi were incubated in sterilized seawater for four weeks at room temperature. Overall, the cell numeration declined rapidly about 10(3) CFU/ ml during starvation, with a tiny rebound at day twenty-one. Scanning electron microscopy revealed rod-shaped cells became sphere with a rippled cell surface. By polymerase chain reaction (PCR) assay, nine genes, named luxR, toxR, vhhB, flaA, topA, fur, rpoS, mreB, ftsZ were detected in the non-starvedi cells...
November 2, 2016: FEMS Microbiology Letters
Rodrigo Rojas, Claudio D Miranda, Javier Santander, Jaime Romero
The VPAP30 strain was isolated as the highly predominant bacteria from an episode of massive larval mortality occurring in a commercial culture of the Chilean scallop Argopecten purpuratus. The main aims of this study were, to characterize and identify the pathogenic strain using biochemical and molecular methods to demonstrate its pathogenic activity on scallop larvae, to characterize its pathogenic properties and to describe the chronology of this pathology. The pathogenic strain was identified as Vibrio tubiashii based on its phenotypic properties and the sequence analysis of its 16S rRNA and housekeeping genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA)...
2016: Frontiers in Microbiology
Dina Elhadi, Li Lv, Xiao-Ran Jiang, Hong Wu, Guo-Qiang Chen
Microbial morphology engineering has recently become interesting for biotechnology. Genes ftsZ and mreB encoding proteins of bacterial fission ring and skeletons, respectively, are essential for cell growth, they both are the most important genes keeping the bacterial shapes including the cell length and width, respectively. Clustered regularly interspaced short palindromic repeats interference, abbreviated as CRISPRi, was for the first time used in this study to regulate expression intensities of ftsZ or/and mreB in E...
September 28, 2016: Metabolic Engineering
Huan Wang, Zhongling Yang, Shuo Du, Lin Ma, Yao Liao, Yujie Wang, Ian Toth, Jiaqin Fan
Identifying phytopathogen proteins that are differentially expressed in the course of establishing an infection is important to better understand the infection process. In vitro approaches, using plant extracts added to culture medium, have been used to identify such proteins but the biological relevance of these findings for in planta infection are often uncertain until confirmed by in vivo studies. Here, we compared proteins of Pectobacterium carotovorum subsp. carotovorum strain PccS1 differentially expressed in LB medium supplemented with extracts of the ornamental plant Zantedeschia elliotiana cultivar 'Black magic' (in vitro) and in plant tissues (in vivo) by two-dimensional electrophoresis coupled with mass spectrometry...
September 27, 2016: Molecular Plant Pathology
Nikolay Ouzounov, Jeffrey P Nguyen, Benjamin P Bratton, David Jacobowitz, Zemer Gitai, Joshua W Shaevitz
Bacteria have remarkably robust cell shape control mechanisms. For example, cell diameter only varies by a few percent across a given population. The bacterial actin homolog, MreB, is necessary for establishment and maintenance of rod shape although the detailed properties of MreB that are important for shape control remained unknown. In this study, we perturb MreB in two ways: by treating cells with the polymerization-inhibiting drug A22 and by creating point mutants in mreB. These perturbations modify the steady-state diameter of cells over a wide range, from 790 ± 30 nm to 1700 ± 20 nm...
September 6, 2016: Biophysical Journal
Yaw Awuni, Shimin Jiang, Robert C Robinson, Yuguang Mu
MreB is an actin-like cytoskeleton protein that plays a vital role in the maintenance of the rod-shaped morphology of many bacteria. S-(3,4-Dichlorobenzyl) isothiourea (A22) is an antibiotic-like small molecule that perturbs the rod cell shape and has been suggested to inhibit MreB by targeting ATP hydrolysis. However, without the elucidation of the structure of the ATP-bound state of MreB in the presence of A22, the mechanism of A22 inhibition is still not clear. Here we apply conventional molecular dynamics simulations to explore the dynamics of the active site of MreB in complex with A22 and different nucleotides...
September 22, 2016: Journal of Physical Chemistry. B
Romain Mercier, Yoshikazu Kawai, Jeff Errington
The peptidoglycan cell wall is a major protective external sheath in bacteria and a key target for antibiotics(1). Peptidoglycan is present in virtually all bacteria, suggesting that it was probably present in the last bacterial common ancestor(2). Cell wall expansion is orchestrated by cytoskeletal proteins related to actin (MreB) and tubulin (FtsZ)(3). FtsZ is a key essential player in a highly organized division machine that directs an invaginating annulus of cell wall peptidoglycan. The recent discovery that cell-wall-less bacteria (L-forms) can grow and divide independently of FtsZ(4,5), provided a means of generating an ftsZ null mutant of Escherichia coli...
2016: Nature Microbiology
Javier Dubert, Jesús L Romalde, Edward J Spinard, David R Nelson, Marta Gomez-Chiarri, Juan L Barja
Orientalis clade has a relevant significance for bivalve aquaculture since it includes the pathogens V. bivalvicida, V. tubiashii subsp. tubiashii and V. tubiashii subsp. europaeus. However, the previous taxonomic description of the subspecies of V. tubiashii shows some incongruities that should be emended. In the genomic age, the comparison between genome assemblies is the key to clarify the taxonomic position of both subspecies. With this purpose, we have tested the ability of MLSA based on eight housekeeping gene sequences (gapA, gyrB, ftsZ, mreB, pyrH, recA, rpoA and topA), different in silico genome to genome comparisons, chemotaxonomic features and phenotypic traits to reclassify the subspecies Vibrio tubiashii subsp...
August 18, 2016: International Journal of Systematic and Evolutionary Microbiology
Qingguo Meng, Peng Liu, Jian Wang, Yinghui Wang, Libo Hou, Wei Gu, Wen Wang
UNLABELLED: Post-translational modifications such as acetylation are an essential regulatory mechanism of protein function. Spiroplasma eriocheiris, with no cell wall and a helical structure, is a novel pathogen of freshwater crustacean. There is no other evidence of acylation (such as succinylation and propionylation) except acetylation genes in S. eriocheiris concise genome. So the acetylation may play an important role in S. eriocheiris. Here, we conducted the first lysine acetylome in S...
October 4, 2016: Journal of Proteomics
Hong Wu, Zhongyun Fan, Xiaoran Jiang, Jinchun Chen, Guo-Qiang Chen
BACKGROUND: Most bacteria are grown in a binary fission way meaning a bacterial cell is equally divided into two. Polyhydroxyalkanoates (PHA) can be accumulated as inclusion bodies by bacteria. The cell division way and morphology have been shown to play an important role in regulating the bacterial growth and PHA storages. RESULTS: The common growth pattern of Escherichia coli was changed to multiple fission patterns by deleting fission related genes minC and minD together, allowing the formation of multiple fission rings (Z-rings) in several positions of an elongated cell, thus a bacterial cell was observed to be divided into more than two daughter cells at same time...
2016: Microbial Cell Factories
Sutharsan Govindarajan, Orna Amster-Choder
Bacterial cells are intricately organized, despite the lack of membrane-bounded organelles. The extremely crowded cytoplasm promotes macromolecular self-assembly and formation of distinct subcellular structures, which perform specialized functions. For example, the cell poles act as hubs for signal transduction complexes, thus providing a platform for the coordination of optimal cellular responses to environmental cues. Distribution of macromolecules is mostly mediated via specialized transport machineries, including the MreB cytoskeleton...
October 2016: Current Opinion in Microbiology
P C Bonez, A P Ramos, K Nascimento, P M Copetti, M E Souza, G G Rossi, V A Agertt, M R Sagrillo, R C V Santos, M M A Campos
The A22 is a chemical compound that acts as a reversible inhibitor of a bacterial cell wall protein MreB leading the rods to the coccoid form. Thus, by changing the bacterial form, many properties can be affected, as the acquisition of nutrients, cell division, the clamping surfaces, motility and pathogenesis. Infections caused by strains of Pseudomonas aeruginosa have great clinical importance because these microorganisms can include more than one resistance mechanism acting together, limiting treatment options...
July 14, 2016: Microbial Pathogenesis
Julien R C Bergeron, Rachel Hutto, Ertan Ozyamak, Nancy Hom, Jesse Hansen, Olga Draper, Meghan E Byrne, Sepehr Keyhani, Arash Komeili, Justin M Kollman
Magnetotactic bacteria possess cellular compartments called magnetosomes that sense magnetic fields. Alignment of magnetosomes in the bacterial cell is necessary for their function, and this is achieved through anchoring of magnetosomes to filaments composed of the protein MamK. MamK is an actin homologue that polymerizes upon ATP binding. Here, we report the structure of the MamK filament at ∼6.5 Å, obtained by cryo-Electron Microscopy. This structure confirms our previously reported double-stranded, non-staggered architecture, and reveals the molecular basis for filament formation...
July 8, 2016: Protein Science: a Publication of the Protein Society
Valerie J Carabetta, Todd M Greco, Andrew W Tanner, Ileana M Cristea, David Dubnau
: N(ε)-Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of the Bacillus subtilis acetylome...
May 2016: MSystems
Yujia Huo, Qiaonan Lu, Xiaowei Zheng, Yuanfang Ma, Feng Lu
OBJECTIVE: To explore effects of FtsZ mutants FtsZ(E75A), FtsZ(R78G) and FtsZ(D82A) on FtsZ self-assembly and interaction of FtsZ with MreB in Escherichia coli strains. METHODS) We constructed FtsZ and its mutant's plasmids by molecular clone and site-directed mutagenesis methods, and purified targeted proteins by affinity chromatography. QN6(ftsZ::yfp-cat), QN7(tsZ::yfp-cat), QN8(ftsZ(R78G)::yfp-cat) and QN9 (ftsZ(D82A):.:yfp-cat) strains were constructed by linear DNA homologous recombination...
February 4, 2016: Wei Sheng Wu Xue Bao, Acta Microbiologica Sinica
Terje M Steinum, Süheyla Karataş, Nora Tandstad Martinussen, Pedro M Meirelles, Fabiano L Thompson, Duncan J Colquhoun
UNLABELLED: The genetic heterogeneity of the close relatives Vibrio anguillarum and Vibrio ordalii, both serious pathogens of fish causing extensive losses in aquaculture, was studied. Eight housekeeping genes, i.e., atpA, ftsZ, gapA, gyrB, mreB, rpoA, topA, and pyrH, were partially sequenced in 116 isolates from diverse fish species and geographical areas. The eight genes appear to be under purifying selection, and the genetic diversity in the total data set was estimated to be 0.767 ± 0...
September 15, 2016: Applied and Environmental Microbiology
Satish Babu Moparthi, Uno Carlsson, Renaud Vincentelli, Bengt-Harald Jonsson, Per Hammarström, Jérôme Wenger
Here, we study and compare the mechanisms of action of the GroEL/GroES and the TRiC chaperonin systems on MreB client protein variants extracted from E. coli. MreB is a homologue to actin in prokaryotes. Single-molecule fluorescence correlation spectroscopy (FCS) and time-resolved fluorescence polarization anisotropy report the binding interaction of folding MreB with GroEL, GroES and TRiC. Fluorescence resonance energy transfer (FRET) measurements on MreB variants quantified molecular distance changes occurring during conformational rearrangements within folding MreB bound to chaperonins...
2016: Scientific Reports
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"