Bacterial protein

FtsZ is conserved in almost all bacteria and is an essential protein for bacterial cell division. The cell division is prevented by the inhibitors against FtsZ’s functions. Thus, FtsZ is known as an attractive, and underexploited novel antibacterial target protein. The aim of this research is searching for new antibacterial agents from 72 plants collected in Central Vietnam.

6p viuchiha 03-01-2025 2 1   Download

The expression of mitochondrial and hydrogenosomal ADP/ATP carriers (AACs) from plants, rat and the anaerobic chytridiomycete fungus Neocallimastix spec. L2 in Escherichia coli allows a functional integration of the recombinant proteins into the bacterial cytoplasmic membrane. For AAC1 and AAC2 from rat, apparent Km values of about 40 lM for ADP, and 105 lM or 140 lM, respectively, for ATP have been determined, similar to the data reported for isolated rat mitochondria.

10p system191 01-06-2013 37 3   Download

The gene fprA of Mycobacterium tuberculosis, encoding a putative protein with 40% identity to mammalian adrenodoxin reductase, was expressed in Escherichia coli and the protein purified to homogeneity. The 50-kDa protein monomer contained one tightly bound FAD, whose fluorescence was fully quenched. FprA showed a low ferric reductase activity, whereas it was very active as a NAD(P)H diaphorase with dyes. Kinetic parameters were determined and the specificity constant (kcat/Km) for NADPH was two orders of magnitude larger than that of NADH....

9p system191 01-06-2013 38 3   Download

Two ORFs, cphA and cphB, encoding proteins CphA and CphB with strong similarities to plant phytochromes and to the cyanobacterial phytochrome Cph1 of Synechocystis sp. PCC 6803 have been identified in the filamentous cyanobacterium Calothrix sp. PCC7601. While CphA carries a cysteine within a highly conserved amino-acid sequence motif, to which the chromophore phytochromobilin is covalently bound in plant phytochromes, in CphB this position is changed into a leucine.

10p system191 01-06-2013 43 4   Download

Oligomerization into multimeric complexes is a prerequisite for the chaperone function of almost all a-crystallin type heat shock proteins (a-Hsp), but the molecular details of complex assembly are poorly understood. The a-Hsp proteins from Bradyrhizobium japonicum are suitable bacterial models for structure-function studies of these ubiquitous stress proteins. They fall into two distinct classes, A and B, display chaperone activity in vitro and form oligomers of  24 subunits.

9p research12 01-06-2013 51 6   Download

Cytochrome c is widely distributed in bacterial species, from mesophiles to thermophiles, and is one of the best-characterized redox proteins in terms of biogenesis, folding, structure, function, and evolution. Experimental molecular biology techniques (gene cloning and expression) have become applicable to cytochrome c, enabling its engineering and manipulation. Heterologous expression systems for cytochromes c in bacteria, for use in mutagenesis studies, have been established by extensive investigation of the biological process by which the functional structure is formed. ...

7p research12 01-06-2013 35 3   Download

DNA cytosine methyltransferaseMspI(M.MspI) must require a different type of interaction of protein with DNA from other bacterial DNA cytosine methyltransferases (m5C-MTases) to evoke the topoisomerase activity that it possesses in addition toDNA-methylation ability. Thismay require a different structural organization in the solution phase from the reported consensus structural arrangement for m5C-MTases.

7p research12 29-04-2013 47 3   Download

Ligand binding by the aryl hydrocarbon receptor (AhR), a member of the bHLH-PAS family of transcriptional reg-ulatory proteins, has been mapped to a region within the second ÔPASÕ domain, a conserved sequence motif ®rst discovered in the Per-ARNT-Sim family of proteins.

6p research12 29-04-2013 43 3   Download

GTP-binding proteins of the Rab family were cloned from human platelets using RT-PCR. Clones corresponding to twonovelRabproteins,Rab31 andRab32, and toRab11A, which had not been detected in platelets previously, were isolated. The coding sequence of Rab31(GenBank acces-sion no. U59877) corresponded to a 194 amino-acid protein of 21.6 kDa. TheRab32sequence was extended to 1000 nucleotides including 630 nucleotides of coding sequence (GenBank accession no.

13p research12 29-04-2013 41 4   Download

Members of the proline-rich antibacterial peptide family, pyrrhocoricin, apidaecin and drosocin appear to kill responsive bacterial species by binding to themultihelical lid region of the bacterial DnaK protein.Pyrrhocoricin, the most potent among these peptides, is nontoxic to healthy mice, andcanprotect these animals frombacterial challenge.

12p research12 23-04-2013 33 3   Download

Hemolin, a plasma protein from lepidopteran insects, is composed of four immunoglobulin domains. Its synthesis is induced by microbial challenge. We investigated the biological functions of hemolin inManduca sexta.It was found to bind to the surface of bacteria and yeast, and caused these micro-organisms to aggregate. Hemolin was demonstrated to bind to lipopolysaccharide (LPS) from Gram-negativebacteriaand to lipoteichoic acid fromGram-positive bacteria.

8p research12 23-04-2013 39 2   Download

mRNA stabilization plays an important role in the changes in protein expression initiated by inducers of inflammation or direct cell stress such as UV light. This study provides evidence that stabilization in response to UV light differs from that induced by proinflammatory stimuli such as bacterial lipopolysaccharide or interleukin (IL)-1. Firstly, UV-induced stabilization is independent of the p38 MAP kinase pathway, which has previously been shown to medi-ate stabilization induced by IL-1 or lipopolysaccharide....

10p tumor12 22-04-2013 45 2   Download

Mitochondrial ribosomal proteins (mrps) of the budding yeast, Saccharomyces cerevisiae, have been extensively characterized genetically and biochemically. However, the list of thegenes encoding individualmrps is still not complete and quite a fewof the mrps are only predicted from their similarity to bacterial ribosomal proteins. We have con-structed a yeast strain in which one of the small subunit proteins, termed Mrp4, was tagged with S-peptide and used for affinity purification of mitochondrial ribosome. ...

12p tumor12 22-04-2013 54 2   Download

14-3-3 proteins play an important role in a multitude of signalling pathways. The interactions between 14-3-3 and other signalling proteins, such as Raf and KSR (kinase suppressor of Ras), occur in a phospho-specific manner. Recently, a phosphorylation-independent interaction has been reported to occur between 14-3-3 and several proteins, for example 5-phosphatase, p75NTR-associated cell death executor (NADE) and the bacterial toxin Exoenzyme S (ExoS), an ADP-ribosyltransferase from Pseudomonas aeruginosa. ...

9p tumor12 22-04-2013 29 3   Download

Era is a highly conserved GTPase essential for bacterial growth. The N-terminal part of Era contains a conserved GTPase domain, whereas the C-terminal part of the protein contains anRNA- andmembrane-binding domain, theKH domain. To investigate whether the binding of Era to 16S rRNA and membrane requires its GTPase activity and whether the GTPase domain is essential for these acti-vities, the N- and C-terminal parts of the Streptococ-cus pneumoniaeEra –Era-N(aminoacids 1–185) andEra-C (amino acids 141–299), respectively – were expressed and purified. ...

9p tumor12 20-04-2013 34 3   Download

A novel nucleosidase enzymatic activity was discovered in the marine spongeAxinella polypoides. This enzyme, desig-nated as ATP N-glycosidase, converts adenosine-5¢-tri-phosphate into adenine and ribose-5-triphosphate. The crude extract ofA.polypoideswas capable of hydrolysing 25lmol ATPÆmin )1 per g wet weight of sponge. The cata-lytic activity of a sponge crude extract permg total protein is comparable with specific activities of purified plant adeno-sine and bacterial AMP nucleosidases.

11p tumor12 20-04-2013 56 3   Download

Recombinant, bacterially expressed apoptin protein induces apoptosis inhuman tumour cell lines but not innormal cells, mimicking the behaviour of ectopically expressed apoptin. Recombinant apoptin is isolated exclusively as a highly stablemultimeric complex of 30–40monomers, with little, if any,a-helical and b-sheet structure. Despite its apparent disorder, multimeric apoptin is biologically active. Here, we present evidence thatmost of the apoptinmoietieswithin the complex may well share a similar conformation.

9p tumor12 20-04-2013 32 3   Download

Drosophilais a powerful model system to study the regula-tory and effector mechanisms of innate immunity. To iden-tify molecules induced in the course of viral infection in this insect, we have developed a model based on intrathoracic injection of the picorna-like DrosophilaCvirus(DCV).We have used MALDI-TOF mass spectrometry to compare the hemolymph of DCV infected flies and control flies. By contrast with the strong humoral response triggered by injectionof bacteriaor fungal spores, we have identifiedonly one molecule induced in the hemolymph of virus infected flies....

10p tumor12 20-04-2013 27 3   Download

We report a comprehensive physicochemical characteriza-tion of a glycoglycerolipid from Mycoplasma fermentans, MfGl-II, in relation to its bioactivityand compared thiswith the respective behaviors of phosphatidylcholine (PC) and a bacterial glycolipid, lipopolysaccharide (LPS) from deep rough mutantSalmonella minnesotastrain R595. Theb«a gel-to-liquid crystalline phase transition behavior of the hydrocarbon chains withTc¼30Cfor MfGl-II as well as for LPS exhibits high similarity between the two glycolipids.

9p tumor12 20-04-2013 33 2   Download

The Tat system catalyzes the transport of folded globular proteins across the bacterial plasma membrane and the chloroplast thylakoid. It recognizes cleavable signal peptides containingacritical twin-argininemotif but little isknownof the overall structure of these peptides. In this report, we have analyzed the secondary structure of the SufI signal peptide, together with those of two nonfunctional variants in which the region around the twin-arginine, RRQFI, is replaced by KKQFI or RRQAA.

8p tumor12 20-04-2013 47 3   Download