Read by QxMD icon Read

crystal toxin

Jung-Wei Chang, Yusuke Sato, Tetsuhiro Ogawa, Takatoshi Arakawa, Shuya Fukai, Shinya Fushinobu, Haruhiko Masaki
Colicins are protein toxins produced by and toxic to Escherichia coli strains. Colicin D consists of an N-terminal domain (NTD), central domain (CD), and C-terminal RNase domain (CRD). The cognate immunity protein, ImmD, is co-synthesized in producer cells to block the toxic tRNase activity of the CRD. Previous studies have reported the crystal structure of CRD/ImmD complex. Colicin D hijacks the surface receptor FepA and the energy transducer TonB system using the NTD for translocation across the outer membrane of the target cells...
June 14, 2018: Journal of Biochemistry
Janja Zajc, Nina Gunde-Cimerman
The fungal genus Wallemia of the order Wallemiales (Wallemiomycotina, Basidiomycota) comprises the most xerotolerant, xerophilic and also halophilic species worldwide. Wallemia spp. are found in various osmotically challenged environments, such as dry, salted, or highly sugared foods, dry feed, hypersaline waters of solar salterns, salt crystals, indoor and outdoor air, and agriculture aerosols. Recently, eight species were recognized for the genus Wallemia , among which four are commonly associated with foods: W...
May 21, 2018: Microorganisms
Do-Hee Kim, Sung-Min Kang, Sung Jean Park, Chenglong Jin, Hye-Jin Yoon, Bong-Jin Lee
Streptococcus pneumonia has attracted increasing attention due to its resistance to existing antibiotics. TA systems are essential for bacterial persistence under stressful conditions such as nutrient deprivation, antibiotic treatment, and immune system attacks. In particular, S. pneumoniae expresses the HicBA TA gene, which encodes the stable HicA toxin and the labile HicB antitoxin. These proteins interact to form a non-toxic TA complex under normal conditions, but the toxin is activated by release from the antitoxin in response to unfavorable growth conditions...
June 6, 2018: Nucleic Acids Research
Ravi P N Mishra, Ravishankar P Yadav, Christopher Jones, Salvatore Nocadello, George Minasov, Ludmilla A Shuvalova, Wayne F Anderson, Akshay Goel
It is established that the immunogenicity of polysaccharides is enhanced by coupling them to carrier proteins. CRM197- , a non-toxic variant of diphtheria toxin is widely used carrier protein for conjugate vaccines. Conventionally, CRM197 is isolated --by fermentation of C. diphtheriae C7 (β197 ) cultures, which often suffers from low yield.  Recently, several recombinant approaches have been reported with robust processes and higher yields, which will improve the affordability of CRM197  based vaccines...
June 6, 2018: Bioscience Reports
Khanppnavar Basavraj, Datta Saumen
BACKGROUND: The nucleotidyl cyclase toxin ExoY is an important virulence determinant of Pseudomonas aeruginosa that causes severe acute and chronic infections in immune-compromised individuals. Additionally, this unique T3SS effector shows a striking preference for cUMP, a newly identified non-canonical secondary messenger. Thereby, ExoY is also considered as a potential tool to study unexplored cUMP signaling pathways. METHODS: The crystal structure of ExoY was determined at 2...
May 30, 2018: Biochimica et Biophysica Acta
Zeyu Wang, Longfa Fang, Zishan Zhou, Sabino Pacheco, Isabel Gómez, Fuping Song, Mario Soberón, Jie Zhang, Alejandra Bravo
The bacterium Bacillus thuringiensis produces several insecticidal proteins, such as the crystal proteins (Cry) and the vegetative insecticidal proteins (Vip). In this work, we report that a specific interaction between two B. thuringiensis toxins creates insecticidal synergism and unravel the molecular basis of this interaction. When applied together, the three-domain Cry toxin, Cry9Aa and the Vip, Vip3Aa, exhibited high insecticidal activity against an important insect pest, the Asiatic rice borer ( Chilo suppressalis )...
June 1, 2018: Journal of Biological Chemistry
Raida Zribi Zghal, Kais Ghedira, Jihen Elleuch, Marwa Kharrat, Slim Tounsi
BLB406 is a novel isolate of Bacillus thuringiensis with a larvicidal activity against Aedes aegypti larvae. It displays original plasmidic and crystal protein patterns. The present work reported molecular and bioinformatic analyses for the genome sequence of BLB406 using MiSeq Illumina next-generation sequencing technology. The reads were assembled by Velvet tool. Using RAST program and PGAAP the genome of BLB406 strain was shown to contain 6297 genes corresponding to 5924 protein coding sequences. The BLB406 genome investigation with BtToxin_scanner program shows that this strain has an original and different combination of toxins compared to the published ones: five cry genes (cry11, cry22, cry2, cry60, cry64) and two distinct vegetative insecticidal vip4 genes...
May 17, 2018: International Journal of Biological Macromolecules
Muhammad Sajid, Ce Geng, Miaomiao Li, Yueying Wang, Hualin Liu, Jinshui Zheng, Donghai Peng, Ming Sun
Despite the successful application of Crystal proteins (Cry) from Bacillus thuringiensis as biological control agents against insects, there is an increasing demand to identify new Cry toxins having higher toxicity and broad spectrum activity against insects and plant parasitic nematodes. To find novel Cry toxins, we screened 100 whole genome sequences of B. thuringiensis. Surprisingly, in addition to full Cry toxins, we found partial sequences, such as typical N-terminal or C-terminal with conserved domains, widely distributed among 20 strains of B...
May 11, 2018: Applied and Environmental Microbiology
Panchada Ch V Govindu, Athul Mohanan, Ashwini Dolle, Konkallu Hanumae Gowd
Conformations of cysteine disulfides were analyzed in X-ray, NMR, and co-crystal structures of peptide toxins retrieved from Protein Data Bank. The parameters side chain torsional angles, disulfide strain energy, inter-atomic Cα/Cβ distances, and Ramachandran angles were used as probes to derive conformational features of cysteine disulfides. Schmidt, 2006 scheme was adapted to classify the disulfide conformations of peptide toxins (Schmidt, B., Ho, L., & Hogg, P. J. (2006). Allosteric disulfide bonds...
May 11, 2018: Journal of Biomolecular Structure & Dynamics
Peng Chen, Liang Tao, Tianyu Wang, Jie Zhang, Aina He, Kwok-Ho Lam, Zheng Liu, Xi He, Kay Perry, Min Dong, Rongsheng Jin
Clostridium difficile infection is the most common cause of antibiotic-associated diarrhea in developed countries. The major virulence factor, C. difficile toxin B (TcdB), targets colonic epithelia by binding to the frizzled (FZD) family of Wnt receptors, but how TcdB recognizes FZDs is unclear. Here, we present the crystal structure of a TcdB fragment in complex with the cysteine-rich domain of human FZD2 at 2.5-angstrom resolution, which reveals an endogenous FZD-bound fatty acid acting as a co-receptor for TcdB binding...
May 11, 2018: Science
Bastian Bräuning, Eva Bertosin, Florian Praetorius, Christian Ihling, Alexandra Schatt, Agnes Adler, Klaus Richter, Andrea Sinz, Hendrik Dietz, Michael Groll
Pore-forming toxins (PFT) are virulence factors that transform from soluble to membrane-bound states. The Yersinia YaxAB system represents a family of binary α-PFTs with orthologues in human, insect, and plant pathogens, with unknown structures. YaxAB was shown to be cytotoxic and likely involved in pathogenesis, though the molecular basis for its two-component lytic mechanism remains elusive. Here, we present crystal structures of YaxA and YaxB, together with a cryo-electron microscopy map of the YaxAB complex...
May 4, 2018: Nature Communications
Kwok-Ho Lam, Stefan Sikorra, Jasmin Weisemann, Hannah Maatsch, Kay Perry, Andreas Rummel, Thomas Binz, Rongsheng Jin
The extreme toxicity of botulinum neurotoxins (BoNTs) relies on their specific cleavage of SNARE proteins, which eventually leads to muscle paralysis. One newly identified mosaic toxin, BoNT/HA (aka H or FA), cleaves VAMP-2 at a unique position between residues L54 and E55, but the molecular basis underlying VAMP-2 recognition of BoNT/HA remains poorly characterized. Here, we report a ∼2.09 Å resolution crystal structure of the light chain protease domain of BoNT/HA (LC/HA). Structural comparison between LC/HA and LC of BoNT/F1 (LC/F1) reveals distinctive hydrophobic and electrostatic features near the active sites, which may explain their different VAMP-2 cleavage sites...
June 1, 2018: Pathogens and Disease
Elham Moazamian, Nima Bahador, Negar Azarpira, Manoochehr Rasouli
Bacillus thuringiensis is one of the most important microorganisms used against cancer cell lines in latest studies all over the world. This study aims to perform the isolation, molecular identification, and to identify novel B. thuringiensis strains that specifically targeting human cancer cell-killing activities in Iran. A total of 88 B. thuringiensis isolates were recovered from Iran. Upon the treatment of the non-hemolytic crystal proteins by proteinase K, five isolates belonging to three biotypes, thuringiensis, kurstaki and sotto of B...
April 23, 2018: Current Microbiology
Robert Gustafsson, Sicai Zhang, Geoffrey Masuyer, Min Dong, Pål Stenmark
Botulinum neurotoxins (BoNTs) are a family of highly dangerous bacterial toxins, with seven major serotypes (BoNT/A-G). Members of BoNTs, BoNT/A1 and BoNT/B1, have been utilized to treat an increasing number of medical conditions. The clinical trials are ongoing for BoNT/A2, another subtype of BoNT/A, which showed promising therapeutic properties. Both BoNT/A1 and BoNT/A2 utilize three isoforms of synaptic vesicle protein SV2 (SV2A, B, and C) as their protein receptors. We here present a high resolution (2...
April 12, 2018: Toxins
Chew Chieng Yeo
GCN5-related N-acetyltransferase (GNAT) is a huge superfamily of proteins spanning the prokaryotic and eukaryotic domains of life. GNAT proteins usually transfer an acetyl group from acetyl-CoA to a wide variety of substrates ranging from aminoglycoside antibiotics to large macromolecules. Type II toxin-antitoxin (TA) modules are typically bicistronic and widespread in bacterial and archael genomes with diverse cellular functions. Recently, a novel family of type II TA toxins was described, which presents a GNAT-fold and functions by acetylating charged tRNA thereby precluding translation...
May 2018: Molecular Microbiology
Asghar Marwat, Hassan Mehmood, Ali Hussain, Muzammil Khan, Asad Ullah, Medha Joshi
The relationship between reactive arthritis and enteric infections caused by Yersinia enterocolitica, Campylobacter jejuni , and Salmonella typhimurium is well documented. Clostridium difficile colitis is a less recognized cause of reactive arthritis. We present a case of a 58-year-old woman with Clostridium difficile colitis complicated by reactive arthritis. A 58-year-old woman with no significant past medical history presented to our hospital with complaints of nonbloody watery diarrhea, abdominal pain for the past 1 week, and right knee pain starting 1 day prior...
January 2018: Journal of Investigative Medicine High Impact Case Reports
Pritam Chattopadhyay, Goutam Banerjee
Bacillus thuringiensis ( Bt ) is a Gram-positive, spore-forming, soil bacterium, which is very popular bio-control agent in agricultural and forestry. In general, B. thuringiensis secretes an array of insecticidal proteins including toxins produced during vegetative growth phase (such as secreted insecticidal protein, Sip; vegetative insecticidal proteins, Vip), parasporal crystalline δ-endotoxins produced during vegetative stationary phase (such as cytolytic toxin, Cyt; and crystal toxin, Cry), and β-exotoxins...
April 2018: 3 Biotech
Jonathan R Davies, Gavin S Hackett, Sai Man Liu, K Ravi Acharya
The binding specificity of botulinum neurotoxins (BoNTs) is primarily a consequence of their ability to bind to multiple receptors at the same time. BoNTs consist of three distinct domains, a metalloprotease light chain (LC), a translocation domain (HN ) and a receptor-binding domain (HC ). Here we report the crystal structure of HC /FA, complementing an existing structure through the modelling of a previously unresolved loop which is important for receptor-binding. Our HC /FA structure also contains a previously unidentified disulphide bond, which we have also observed in one of two crystal forms of HC /A1...
2018: PeerJ
Shuaiqi Guo, David N Langelaan, Sean W Phippen, Steven P Smith, Ilja K Voets, Peter L Davies
Repeats-in-toxin (RTX) adhesins are present in many Gram-negative bacteria to facilitate biofilm formation. Previously, we reported that the 1.5-MDa RTX adhesin (MpIBP) from the Antarctic bacterium, Marinomonas primoryensis, is tethered to the bacterial cell surface via its N-terminal Region I (RI). Here, we show the detailed structural features of RI. It has an N-terminal periplasmic retention domain (RIN), a central domain (RIM) that can insert into the β-barrel of an outer-membrane pore protein during MpIBP secretion, and three extracellular domains at its C terminus (RIC) that transition the protein into the extender region (RII)...
March 25, 2018: FEBS Journal
Shaista Javaid, Sehrish Naz, Imran Amin, Georg Jander, Zaheer Ul-Haq, Shahid Mansoor
Sucking pests pose a serious agricultural challenge, as available transgenic technologies such as Bacillus thuringiensis crystal toxins (Bt) are not effective against them. One approach is to produce fusion protein toxins for the control of these pests. Two protein toxins, Hvt (ω-atracotoxin from Hadronyche versuta) and onion leaf lectin, were translationally fused to evaluate the negative effects of fusion proteins on Phenacoccus solenopsis (mealybug), a phloem-feeding insect pest. Hvt was cloned both N-terminally (HL) and then C-terminally (LH) in the fusion protein constructs, which were expressed transiently in Nicotiana tabacum using a Potato Virus X (PVX) vector...
March 19, 2018: 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"