Bacillus cereus nositelj plazmida pXO1 s genom pag uzrokuje u goveda s oslabljenim imunosnim sustavom smrtonosnu septikemiju sličnu bedrenici - kratko priopćenje.

Bacillus cereus is ubiquitous in nature and while most isolates appear to be harmless, some are associated with food-borne illnesses, wound infections, endocarditis, osteomyelitis, endophthalmitis and urinary tract infections in humans. Recently, a few isolates have been identified as the causative agents of anthrax-like severe pneumonia in humans, and these isolates were found to harbor most of the B. anthracis virulence plasmid pXO1. Here we report the characterization of three clinical B. cereus isolates recovered from heart blood and spleen samples of cattle which had died with ‘anthrax like’ symptoms. Apart from the cultural characterizations, primers targeting the 16S rRNA gene of B. cereus were designed and used on these isolates. The isolates were found to harbor the pXO1 plasmid and lacked pXO2 plasmid. Further characterization of the pXO1 plasmid revealed that the isolates contained pag, lef and cya genes, which code for protective antigen, lethal factor and edema factor toxins responsible for eliciting an ‘anthrax like disease’ in cattle. The sequencing and phylogenetic analysis of partial pag gene sequences of B. cereus isolates were identical to pag gene sequences on the pXO1 of B. anthracis. In a pathogenicity test on mice, B. cereus isolates, when inoculated by the intra peritoneal route, caused mortality of the mice within 6 hours post inoculation.Bacillus cereus je posvudašnja bakterija. Većina izolata te bakterije je neškodljiva, a neki mogu uzrokovati bolesti koje se prenose hranom, infekcije rana, endokarditis, osteomijelitis, endoftalmitis i infekcije mokraćnog sustava u ljudi. Nedavno je identificirano nekoliko izolata koji uzrokuju tešku upalu pluća u čovjeka sličnu onoj kod bedrenice. Ti izolati većinom nose virulentni plazmid pXO1 vrste B. anthracis. U ovom radu određena su obilježja triju kliničkih izolata vrste B. cereus izdvojenih iz krvi sadržane u srcu i uzoraka slezene goveda uginulih pod znakovima sličnima bedrenici. Osim određivanja kulturalnih obilježja, pripremljene su i početnice za gen 16S rRNA vrste B. cereus koje su bile rabljene za identifikaciju izolata. Ustanovljeno je da izolati nose plazmid pXO1, a nedostaje im plazmid pXO2. Daljnja karakterizacija plazmida pXO1 pokazala je da izolati sadrže gene pag, lef i cya koji kodiraju za zaštitni antigen, letalni čimbenik i edemski čimbenik, toksine koji su odgovorni za pojavu bolesti u goveda slične bedrenici. Određivanje slijeda i filogenetska analiza dijela sekvencija gena pag izolata B. cereus pokazala je da su oni istovjetni sekvencijama gena pag na pXO1 bakterije B. anthracis. U testu patogenosti na miševima, izolati B. cereus prouzročili su njihovo uginuće šest sati nakon intraperitonejske inokulacije

Activation of - N=CH - bond in a Schiff base by divalent nickel monitored by NMR evidence

The Schiff base, 2-salicylidene-4-aminophenyl benzimidazole in ethanol undergoes activation of -N=CH- bond by Ni 2+ in the presence of ammonia or primary alkyl amine to produce nickel complexes of the formula Nio-C 6H 4(O)CH NR 2. n H 2O R=H, Me; n=0; R=Et, n=0.5 and 4-aminophenyl benzimidazole. The products have been identified by elemental analysis, magnetic susceptibility measurements and IR, ESR, mass and extensive NMR spectral studies. The possible mechanism for the activation of -N=CH - bond has also been proposed. Copyright © 2012 John Wiley & Sons, Ltd

Synthesis and spectral studies of 2-salicylidine-4-aminophenyl benzimidazole and its reaction with divalent Zn, Cd and Hg: Crystal structure of the cadmium bromide complex

2-salicylidine-4-aminophenyl benzimidazole (SAPbzlH, LH) has been synthesised and its complexes, formulated as ZnX2Ly.nH2O (X = Cl, y = 1.5, n = 1; X = Br, y = 2, n = 2; X = CH3COO, y = 1.5, n = 2), CdX2L.CH3OH.0.5H2O (X = Cl, Br) and HgX2L.nH2O (X = Cl, n = 2; X = Br, n = 0), have been characterised. A single crystal X-ray diffraction study of Cd 2Br4L2.2CH3OH.H2O has revealed its binuclear structure with dibromide and SAPbzlH bridges, the environment around each metal ion being distorted trigonal bipyramidal. A similar structure is envisaged for the chloride analogue of cadmium as well as the mercury complexes

Structural and functional analysis of SMO-1, the SUMO homolog in <i>Caenorhabditis elegans</i>

<div><p>SUMO proteins are important post-translational modifiers involved in multiple cellular pathways in eukaryotes, especially during the different developmental stages in multicellular organisms. The nematode <i>C</i>. <i>elegans</i> is a well known model system for studying metazoan development and has a single SUMO homolog, SMO-1. Interestingly, SMO-1 modification is linked to embryogenesis and development in the nematode. However, high-resolution information about SMO-1 and the mechanism of its conjugation is lacking. In this work, we report the high-resolution three dimensional structure of SMO-1 solved by NMR spectroscopy. SMO-1 has flexible N-terminal and C-terminal tails on either side of a rigid beta-grasp folded core. While the sequence of SMO-1 is more similar to SUMO1, the electrostatic surface features of SMO-1 resemble more with SUMO2/3. SMO-1 can bind to typical SUMO Interacting Motifs (SIMs). SMO-1 can also conjugate to a typical SUMOylation consensus site as well as to its natural substrate HMR-1. Poly-SMO-1 chains were observed <i>in-vitro</i> even though SMO-1 lacks any consensus SUMOylation site. Typical deSUMOylation enzymes like Senp2 can cleave the poly-SMO-1 chains. Despite being a single gene, the SMO-1 structure allows it to function in a large repertoire of signaling pathways involving SUMO in <i>C</i>. <i>elegans</i>. Structural and functional features of SMO-1 studies described here will be useful to understand its role in development.</p></div

Comparison of structures and electrostatic surface potential between SMO-1 and its SUMO homologues.

<p>(A), (B) and (C) The top panel shows the cartoon representation of SUMO1, SMO-1 and SUMO2 (all in orange). The SIM interacting region of SUMO1 and SUMO2 is marked by an oval in broken line. The middle panel shows the APBS calculated (at 298 K) electrostatic surface potential of respective proteins in the orientation shown in top panel. The bottom panel shows the same electrostatic surface potential at an orientation rotated 180 degree about the vertical shown as shown. Color gradient scheme of the electrostatic surface is shown for each surface. Positively charged surfaces are colored blue, neutral surfaces are in white and negatively charged surfaces are in red. The unit of the color gradient shown is kcal/(mol.<i>e</i>).</p

Backbone dynamics in SMO-1 protein at picosecond-nanosecond timescale.

<p>¹⁵N longitudinal relaxation times constants T1 (A), ¹⁵N transverse relaxation time constants T2 (B) and {¹H}-¹⁵N hetNOEs values (C) of backbone amides for all observable residues in SMO-1. Lower T1 values, higher T2 values and hetNOEs closer to zero or less than zero indicated higher ps-ns backbone dynamics. The secondary structure elements corresponding to SMO-1 residues are shown in green line above each plot. The standard error bars of the fitted parameters values are shown for each plot.</p

NMR and refinement statistics of SMO-1.

<p>NMR and refinement statistics of SMO-1.</p

SMO-1 forms chains in <i>in vitro</i> SUMOylation assays.

<p>(A) Sequence of FITC fluorophore labelled peptide used as substrate in <i>in vitro</i> SUMOylation assays. The lysines competent for SUMOylation are in bigger font and in bold face. All subsequent images were obtained by observing FITC fluorescence at 519 nm unless otherwise mentioned. (B) SUMOylation reaction products with peptide shown in (A) and SUMO1/SMO-1 resolved on SDS-PAGE gel. The negative control is lane labelled “no ATP”. Bands of free peptide and peptide conjugated with one, two or multiple (n) SMO-1 are marked. The molecular weight marker positions are indicated. (C) Time course of SUMOylation reaction between peptide shown in (A) and SMO-1. Different time points are indicated. O/N means overnight (~12 hours) incubation of reaction. Band identities and molecular weight marker positions are shown as in (B). (D) SUMOylation reaction using FITC-labelled SMO-1 and in absence of any other peptide substrate. The reaction products and the negative control (without ATP) are resolved and marked. (E) De-conjugation of SUMOylated peptides by SENP2 enzyme. The SUMOylation reaction products shown in (B) were run with or without treatment with SENP2. (F) De-conjugation reaction of SMO-1-YFP construct with SENP2. The SDS-PAGE gel is imaged by observing YFP fluorescence. (G) SUMOylation reaction between FITC-labelled SMO-1 and HMR-1A, a known protein substrate of SMO-1 in <i>C</i>. <i>elegans</i>. The reaction product band is marked. Negative controls–without ATP and without HMR-1A is also shown. (H) SUMOylation reaction described in (G) is shown with the negative control where all lysines of HMR-1A were mutated to arginines to create the SUMOylation incompetent HMR-1A-K2R construct.</p

Sequence and structural examination of SMO-1.

<p>(A) Multiple sequence alignment of SMO-1 with its homologues SUMO1 and SUMO2. Identical residues across the homologues are boxed in black while similar residues are boxed in grey. (B) ¹⁵N-HSQC of SMO-1 protein is shown with backbone amide peaks labelled by residue numbers. The side chain amides are connected by dashed lines. The folded peaks of arginine side chains are marked by an asterisk.</p

NMR solution structure of SMO-1.

<p>(A) 20 lowest energy NMR solution structures of SMO-1calculated by CYANA. The SMO-1 chains (in orange) are depicted in cartoon representation. (B) The best model structure of SMO-1 protein is shown in orange. The chain termini and secondary elements are labelled.</p