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https://www.readbyqxmd.com/read/28083564/direct-heme-uptake-by-phytoplankton-associated-roseobacter-bacteria
#1
Shane L Hogle, Bianca Brahamsha, Katherine A Barbeau
Iron is an essential micronutrient and can limit the growth of both marine phytoplankton and heterotrophic bacterioplankton. In this study, we investigated the molecular basis of heme transport, an organic iron acquisition pathway, in phytoplankton-associated Roseobacter bacteria and explored the potential role of bacterial heme uptake in the marine environment. We searched 153 Roseobacter genomes and found that nearly half contained putative complete heme transport systems with nearly the same synteny. We also examined a publicly available coculture transcriptome and found that Roseobacter strain Sulfitobacter sp...
January 2017: MSystems
https://www.readbyqxmd.com/read/28077872/structural-basis-for-nutrient-acquisition-by-dominant-members-of-the-human-gut-microbiota
#2
Amy J Glenwright, Karunakar R Pothula, Satya P Bhamidimarri, Dror S Chorev, Arnaud Baslé, Susan J Firbank, Hongjun Zheng, Carol V Robinson, Mathias Winterhalter, Ulrich Kleinekathöfer, David N Bolam, Bert van den Berg
The human large intestine is populated by a high density of microorganisms, collectively termed the colonic microbiota, which has an important role in human health and nutrition. The survival of microbiota members from the dominant Gram-negative phylum Bacteroidetes depends on their ability to degrade dietary glycans that cannot be metabolized by the host. The genes encoding proteins involved in the degradation of specific glycans are organized into co-regulated polysaccharide utilization loci, with the archetypal locus sus (for starch utilisation system) encoding seven proteins, SusA-SusG...
January 11, 2017: Nature
https://www.readbyqxmd.com/read/28056815/comparative-genomics-of-host-adaptive-traits-in-xanthomonas-translucens-pv-graminis
#3
Lena Hersemann, Daniel Wibberg, Jochen Blom, Alexander Goesmann, Franco Widmer, Frank-Jörg Vorhölter, Roland Kölliker
BACKGROUND: Xanthomonas translucens pathovars differ in their individual host ranges among Poaceae. As the causal agent of bacterial wilt in Italian ryegrass (Lolium multiflorum Lam.), X. translucens pv. graminis (Xtg) is one of the most important bacterial pathogens in temperate grassland regions. The genomes of six Xtg strains from Switzerland, Norway, and New Zealand were sequenced in order to gain insight into conserved genomic traits from organisms covering a wide geographical range...
January 5, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28036380/two-component-signaling-system-vgrrs-directly-senses-extracytoplasmic-and-intracellular-iron-to-control-bacterial-adaptation-under-iron-depleted-stress
#4
Li Wang, Yue Pan, Zhi-Hui Yuan, Huan Zhang, Bao-Yu Peng, Fang-Fang Wang, Wei Qian
Both iron starvation and excess are detrimental to cellular life, especially for animal and plant pathogens since they always live in iron-limited environments produced by host immune responses. However, how organisms sense and respond to iron is incompletely understood. Herein, we reveal that in the phytopathogenic bacterium Xanthomonas campestris pv. campestris, VgrS (also named ColS) is a membrane-bound receptor histidine kinase that senses extracytoplasmic iron limitation in the periplasm, while its cognate response regulator, VgrR (ColR), detects intracellular iron excess...
December 2016: PLoS Pathogens
https://www.readbyqxmd.com/read/28035693/identification-of-a-u-zn-cu-responsive-global-regulatory-two-component-system-in-caulobacter-crescentus
#5
Dan M Park, K Wesley Overton, Megan J Liou, Yongqin Jiao
Despite the well-known toxicity of uranium (U) to bacteria, little is known about how cells sense and respond to U. The recent finding of a U-specific stress response in Caulobacter crescentus has provided a foundation for studying the mechanisms of U- perception in bacteria. To gain insight into this process, we used a forward genetic screen to identify the regulatory components governing expression of the urcA promoter (PurcA ) that is strongly induced by U. This approach unearthed a previously uncharacterized two-component system, named UzcRS, which is responsible for U-dependent activation of PurcA ...
December 30, 2016: Molecular Microbiology
https://www.readbyqxmd.com/read/28031282/tonb-dependent-heme-hemoglobin-utilization-by-caulobacter-crescentus-huta
#6
Heloise Balhesteros, Yan Shipelskiy, Noah Long, Aritri Majumdar, Benjamin B Katz, Naara M Santos, Laura Leaden, Salete M Newton, Marilis V Marques, Phillip E Klebba
: Siderophore nutrition tests with Caulobacter crescentus strain NA1000 revealed that it utilized a variety of ferric hydroxamate siderophores, including asperchromes, ferrichromes, ferrichrome A, malonichrome and ferric aerobactin, as well as hemin and hemoglobin. C. crescentus did not transport ferrioxamine B or ferric catecholates. Because it did not use ferric enterobactin, the catecholate aposiderophore was an effective agent for iron deprivation. We determined the kinetics and thermodynamics of [(59)Fe]-apoferrichrome and [(59)Fe]-citrate binding and transport by NA1000...
December 28, 2016: Journal of Bacteriology
https://www.readbyqxmd.com/read/28018865/catecholamine-stimulated-growth-of-aeromonas-hydrophila-requires-the-tonb2-energy-transduction-system-but-is-independent-of-the-amonabactin-siderophore
#7
Yuhao Dong, Jin Liu, Maoda Pang, Hechao Du, Nannan Wang, Furqan Awan, Chengping Lu, Yongjie Liu
The growth-stimulating effects of catecholamine stress hormones have been demonstrated in many pathogens. However, catecholamine-induced growth and its underlying mechanisms remain poorly understood in Aeromonas hydrophila. The present study sought to demonstrate that norepinephrine (NE), epinephrine (Epi), dopamine (Dopa), and L-dopa stimulate the growth of A. hydrophila in iron-restricted media containing serum. NE exhibited the strongest growth stimulation, which could be blocked by adrenergic antagonists...
2016: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/27935943/confined-mobility-of-tonb-and-fepa-in-escherichia-coli-membranes
#8
Yoriko Lill, Lorne D Jordan, Chuck R Smallwood, Salete M Newton, Markus A Lill, Phillip E Klebba, Ken Ritchie
The important process of nutrient uptake in Escherichia coli, in many cases, involves transit of the nutrient through a class of beta-barrel proteins in the outer membrane known as TonB-dependent transporters (TBDTs) and requires interaction with the inner membrane protein TonB. Here we have imaged the mobility of the ferric enterobactin transporter FepA and TonB by tracking them in the membranes of live E. coli with single-molecule resolution at time-scales ranging from milliseconds to seconds. We employed simple simulations to model/analyze the lateral diffusion in the membranes of E...
2016: PloS One
https://www.readbyqxmd.com/read/27915254/ompf-of-pectobacterium-carotovorum-subsp-carotovorum-pcc3-is-required-for-carocin-d-sensitivity
#9
Jeong-A Lim, Jisoo Hong, Jonguk Kim, Sunggi Heu, Eunjung Roh
Carocin D is a bacteriocin produced by Pectobacterium carotovorum subsp. carotovorum Pcc21. Carocin D inhibits the growth of P carotovorum subsp. carotovorum and closely related strains. Pectobacterium carotovorum subsp. carotovorum is a causative bacterium for soft rot disease and leads to severe economic losses. Bacteriocins recognize and interact with a specific membrane protein of target bacteria as a receptor. To identify the receptor responsible for carocin D recognition, mutants that underwent a phenotypic change from carocin D sensitivity to carocin D insensitivity were screened...
December 2016: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/27845444/investigation-of-tbfa-in-riemerella-anatipestifer-using-plasmid-based-methods-for-gene-over-expression-and-knockdown
#10
MaFeng Liu, MengYi Wang, DeKang Zhu, MingShu Wang, RenYong Jia, Shun Chen, KunFeng Sun, Qiao Yang, Ying Wu, XiaoYue Chen, Francis Biville, AnChun Cheng
Riemerella anatipestifer is a duck pathogen that has caused serious economic losses to the duck industry worldwide. Despite this, there are few reported studies of the physiological and pathogenic mechanisms of Riemerella anatipestifer infection. In previous study, we have shown that TonB1 and TonB2 were involved in hemin uptake. TonB family protein (TbfA) was not investigated, since knockout of this gene was not successful at that time. Here, we used a plasmid based gene over-expression and knockdown to investigate its function...
November 15, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27807137/methanobactin-transport-machinery
#11
Laura M K Dassama, Grace E Kenney, Soo Y Ro, Eliza L Zielazinski, Amy C Rosenzweig
Methanotrophic bacteria use methane, a potent greenhouse gas, as their primary source of carbon and energy. The first step in methane metabolism is its oxidation to methanol. In almost all methanotrophs, this chemically challenging reaction is catalyzed by particulate methane monooxygenase (pMMO), a copper-dependent integral membrane enzyme. Methanotrophs acquire copper (Cu) for pMMO by secreting a small ribosomally produced, posttranslationally modified natural product called methanobactin (Mbn). Mbn chelates Cu with high affinity, and the Cu-loaded form (CuMbn) is reinternalized into the cell via an active transport process...
November 15, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27806272/allosteric-signaling-is-bidirectional-in-an-outer-membrane-transport-protein
#12
Arthur Sikora, Benesh Joseph, Morgan Matson, Jacob R Staley, David S Cafiso
In BtuB, the Escherichia coli TonB-dependent transporter for vitamin B12, substrate binding to the extracellular surface unfolds a conserved energy coupling motif termed the Ton box into the periplasm. This transmembrane signaling event facilitates an interaction between BtuB and the inner-membrane protein TonB. In this study, continuous-wave and pulse electron paramagnetic resonance in a native outer-membrane preparation demonstrate that signaling also occurs from the periplasmic to the extracellular surface in BtuB...
November 1, 2016: Biophysical Journal
https://www.readbyqxmd.com/read/27804963/evidence-of-prokaryote-like-protein-associated-with-nickel-resistance-in-higher-plants-horizontal-transfer-of-tonb-dependent-receptor-protein-in-betula-genus-or-de-novo-mechanisms
#13
G Theriault, K K Nkongolo
Mechanisms of metal resistance have been reported in many plants but knowledge in woody species is scarce. The TonB-dependent receptors family (TBDTs) is a large group of proteins that facilitate the transport of molecules across the membrane of Gram-negative bacteria. Some evidence exists that TBDTs are involved in metal stress. The existence of a TonB-like mechanism in non-prokaryotes has not been established. The recent development of the Betula papyrifera (white birch) transcriptome has allowed the discovery of genes involved in plant adaptation to stress...
November 2, 2016: Heredity
https://www.readbyqxmd.com/read/27796364/structure-of-the-bacterial-plant-ferredoxin-receptor-fusa
#14
Rhys Grinter, Inokentijs Josts, Khedidja Mosbahi, Aleksander W Roszak, Richard J Cogdell, Alexandre M J J Bonvin, Joel J Milner, Sharon M Kelly, Olwyn Byron, Brian O Smith, Daniel Walker
Iron is a limiting nutrient in bacterial infection putting it at the centre of an evolutionary arms race between host and pathogen. Gram-negative bacteria utilize TonB-dependent outer membrane receptors to obtain iron during infection. These receptors acquire iron either in concert with soluble iron-scavenging siderophores or through direct interaction and extraction from host proteins. Characterization of these receptors provides invaluable insight into pathogenesis. However, only a subset of virulence-related TonB-dependent receptors have been currently described...
October 31, 2016: Nature Communications
https://www.readbyqxmd.com/read/27760693/iron-acquisition-pathways-and-colonization-of-the-inflamed-intestine-by-salmonella-enterica-serovar-typhimurium
#15
Luciana F Costa, Juliana P S Mol, Ana Patricia C Silva, Auricélio A Macêdo, Teane M A Silva, Geraldo E S Alves, Sebastian Winter, Maria G Winter, Eric M Velazquez, Mariana X Byndloss, Andreas J Bäumler, Renée M Tsolis, Tatiane A Paixão, Renato L Santos
Salmonella enterica serotype Typhimurium is able to expand in the lumen of the inflamed intestine through mechanisms that have not been fully resolved. Here we utilized streptomycin-pretreated mice and dextran sodium sulfate (DSS)-treated mice to investigate how pathways for S. Typhimurium iron acquisition contribute to pathogen expansion in the inflamed intestine. Competitive infection with an iron uptake-proficient S. Typhimurium strain and mutant strains lacking tonB feoB, feoB, tonB or iroN in streptomycin pretreated mice demonstrated that ferric iron uptake requiring IroN and TonB conferred a fitness advantage during growth in the inflamed intestine...
December 2016: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/27720988/salt-inducible-protein-splicing-in-cis-and-trans-by-inteins-from-extremely-halophilic-archaea-as-a-novel-protein-engineering-tool
#16
Annika Ciragan, A Sesilja Aranko, Igor Tascon, Hideo Iwaï
Intervening protein sequences (inteins) from extremely halophilic haloarchaea can be inactive under low salinity but could be activated by increasing salt contents to a specific concentration for each intein. The halo-obligatory inteins confer high solubility under both low and high salinity conditions. We showed the broad utility of salt-dependent protein splicing in cis and trans by demonstrating backbone cyclization, self-cleavage for purification, and scarless protein ligation for segmental isotopic labeling...
October 6, 2016: Journal of Molecular Biology
https://www.readbyqxmd.com/read/27705764/role-of-the-native-outer-membrane-environment-on-the-transporter-btub
#17
Curtis Balusek, James C Gumbart
BtuB is a TonB-dependent transporter that permits the high-affinity binding and transport of cobalamin (CBL), or vitamin B12, across the asymmetric outer membrane (OM) of Gram-negative bacteria. It has been shown that Ca(2+) binding is necessary for high-affinity binding of CBL to BtuB, and earlier simulations suggested that calcium ions serve to stabilize key substrate-binding extracellular loops. However, those simulations did not account for the lipopolysaccharides in the OM. To illuminate the roles of both Ca(2+) and lipopolysaccharides in protein functionality, we performed simulations of apo and Ca(2+)-loaded BtuB in symmetric and asymmetric bilayers...
October 4, 2016: Biophysical Journal
https://www.readbyqxmd.com/read/27693114/tonb-dependent-ligand-trapping-in-the-btub-transporter
#18
Allan Mills, Hai-Tuong Le, Franck Duong
TonB-dependent transporters are β-barrel outer membrane proteins occluded by a plug domain. Upon ligand binding, these transporters extend a periplasmic motif termed the TonB box. The TonB box permits the recruitment of the inner membrane protein complex TonB-ExbB-ExbD, which drives import of ligands in the cell periplasm. It is unknown precisely how the plug domain is moved aside during transport nor have the intermediate states between TonB recruitment and plug domain movement been characterized biochemically...
December 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27634541/pangenome-and-immuno-proteomics-analysis-of-acinetobacter-baumannii-strains-revealed-the-core-peptide-vaccine-targets
#19
Afreenish Hassan, Anam Naz, Ayesha Obaid, Rehan Zafar Paracha, Kanwal Naz, Faryal Mehwish Awan, Syed Aun Muhmmad, Hussnain Ahmed Janjua, Jamil Ahmad, Amjad Ali
BACKGROUND: Acinetobacter baumannii has emerged as a significant nosocomial pathogen during the last few years, exhibiting resistance to almost all major classes of antibiotics. Alternative treatment options such as vaccines tend to be most promising and cost effective approaches against this resistant pathogen. In the current study, we have explored the pan-genome of A. baumannii followed by immune-proteomics and reverse vaccinology approaches to identify potential core vaccine targets...
2016: BMC Genomics
https://www.readbyqxmd.com/read/27624128/klebsiella-pneumoniae-siderophores-induce-inflammation-bacterial-dissemination-and-hif-1%C3%AE-stabilization-during-pneumonia
#20
Victoria I Holden, Paul Breen, Sébastien Houle, Charles M Dozois, Michael A Bachman
UNLABELLED: Klebsiella pneumoniae is a Gram-negative pathogen responsible for a wide range of infections, including pneumonia and bacteremia, and is rapidly acquiring antibiotic resistance. K. pneumoniae requires secretion of siderophores, low-molecular-weight, high-affinity iron chelators, for bacterial replication and full virulence. The specific combination of siderophores secreted by K. pneumoniae during infection can impact tissue localization, systemic dissemination, and host survival...
2016: MBio
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