Expression, purification and structural characterization of resveratrol synthase from Polygonum cuspidatum.

Polygonum cuspidatum, an important medicinal plant in China, is a rich source of resveratrol compounds, and its synthesis related resveratrol synthase (RS) gene is highly expressed in stems. The sequence of the resveratrol synthase was amplified with specific primers. Sequence comparison showed that it was highly homologous to the STSs.

Dose Effects of Orally Administered Suspension on Colonic Microbiota in Healthy Mice.

Oral supplemented nutraceuticals derived from food sources are surmised to improve the human health through interaction with the gastrointestinal bacteria. However, the lack of fundamental quality control and authoritative consensus (e.g.

Crosstalk between cancer and immune cells: Role of tumor-associated macrophages in the tumor microenvironment.

Tumor microenvironment is a complex system that contains multiple cells and cytokines. Among the multiple immune cells, macrophage is particularly abundant and plays an important role throughout the tumor progression process, namely, tumor-associated macrophage (TAM) in this special tumor microenvironment. Many kinds of cytokines from TAMs and other immune cells in tumor niche are involved in the linkage of inflammation, immunity and tumorigenesis.

Cyclic Dimeric Guanosine Monophosphate: Activation and Inhibition of Innate Immune Response.

Cyclic dimeric guanosine monophosphate (c-di-GMP) is a universally conserved second messenger that contributes to the pathogenicity of numerous bacterial species. In recent years, growing evidence has shown that bacterial extracellular c-di-GMP can interact with the innate immune system and regulate host immune responses. This review summarizes our current understanding on the dual roles of bacterial c-di-GMP in pathogen-host interaction: activation of the antibacterial innate immune response through the cytosolic surveillance pathway and inhibition of innate immune defense for iron restriction.

The Small Regulatory Antisense RNA PilR Affects Pilus Formation and Cell Motility by Negatively Regulating in sp. PCC 6803.

Pili are found on the surface of many bacteria and play important roles in cell motility, pathogenesis, biofilm formation, and sensing and reacting to environmental changes. Cell motility in the model cyanobacterium sp. PCC 6803 relies on expression of the putative operon.

Uncovering Drug Mechanism of Action by Proteome Wide- Identification of Drug-Binding Proteins.

Small molecule drugs obtained from synthetic compounds or natural products show their therapeutic effects by specifically binding to one or a few target proteins and modulating their functions. In contrast, undesirable drug-protein interactions may provoke harmful side effects. Furthermore, drug-protein interactions also play roles in drug activation, transport, metabolism and regulation of drug resistance.

Structure of ThiM from Vitamin B1 biosynthetic pathway of Staphylococcus aureus - Insights into a novel pro-drug approach addressing MRSA infections.

Infections caused by the methicillin-resistant Staphylococcus aureus (MRSA) are today known to be a substantial threat for global health. Emerging multi-drug resistant bacteria have created a substantial need to identify and discover new drug targets and to develop novel strategies to treat bacterial infections. A promising and so far untapped antibiotic target is the biosynthesis of vitamin B1 (thiamin).

High resolution structures of Plasmodium falciparum GST complexes provide novel insights into the dimer-tetramer transition and a novel ligand-binding site.

Protection from oxidative stress and efficient redox regulation are essential for malarial parasites which have to grow and multiply rapidly in pro-oxidant rich environments. Therefore, redox active proteins currently belong to the most attractive antimalarial drug targets. The glutathione S-transferase from Plasmodium falciparum (PfGST) is a redox active protein displaying a peculiar dimer-tetramer transition that causes full enzyme-inactivation.

Purification, crystallization and preliminary crystallographic analysis of a ribosome-recycling factor from Thermoanaerobacter tengcongensis (TteRRF).

Ribosome-recycling factor (RRF) plays an essential role in the fourth step of protein synthesis in prokaryotes. RRF combined with elongation factor G (EF-G) disassembles the post-termination ribosome complex and recycles the protein synthesis machine for the next round of translation. A reductive-methylation-modified RRF from Thermoanaerobacter tengcongensis (TteRRF) has been crystallized using the vapour-diffusion method.

Structural insights into the T6SS effector protein Tse3 and the Tse3-Tsi3 complex from Pseudomonas aeruginosa reveal a calcium-dependent membrane-binding mechanism.

The opportunistic pathogen Pseudomonas aeruginosa uses the type VI secretion system (T6SS) to deliver the muramidase Tse3 into the periplasm of rival bacteria to degrade their peptidoglycan (PG). Concomitantly, P. aeruginosa uses the periplasm-localized immunity protein Tsi3 to prevent potential self-intoxication caused by Tse3, and thus gains an edge over rival bacteria in fierce niche competition.

Protein preparation, crystallization and preliminary X-ray analysis of Polygonum cuspidatum bifunctional chalcone synthase/benzalacetone synthase.

The chalcone synthase (CHS) superfamily of type III polyketide synthases (PKSs) generate the backbones of a variety of plant secondary metabolites. An active bifunctional chalcone synthase/benzalacetone synthase (CHS/BAS) from Polygonum cuspidatum was overexpressed in Escherichia coli as a C-terminally polyhistidine-tagged fusion protein, purified to homogeneity and crystallized using polyethylene glycol 4000 as a precipitant. The production of well shaped crystals of the complex between PcPKS1 and benzalacetone was dependent on the presence of sorbitol and barium chloride as additives.

Expression, purification and preliminary crystallographic analysis of the T6SS effector protein Tse3 from Pseudomonas aeruginosa.

Pseudomonas aeruginosa uses the type VI secretion system (T6SS) to inject effector proteins into rival cells in niche competition. Tse3, one of the effectors of T6SS, is delivered into the periplasm of recipient cells. Tse3 functions as a muramidase that degrades the β-1,4-linkage between N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) in peptidoglycan, thus leading to lysis of the recipient cells and providing a competitive advantage to the donor cells.

Structural insight into how Pseudomonas aeruginosa peptidoglycanhydrolase Tse1 and its immunity protein Tsi1 function.

Tse1 (Tse is type VI secretion exported), an effector protein produced by Pseudomonas aeruginosa, is an amidase that hydrolyses the γ-D-glutamyl-DAP (γ-D-glutamyl-L-meso-diaminopimelic acid) linkage of the peptide bridge of peptidoglycan. P. aeruginosa injects Tse1 into the periplasm of recipient cells, degrading their peptidoglycan, thereby helping itself to compete with other bacteria.

Crystallization and preliminary crystallographic analysis of a calcineurin B-like protein 1 (CBL1) mutant from Ammopiptanthus mongolicus.

Calcineurin B-like protein 1 (CBL1) is a calcium sensor in plants. It transmits the calcium signal through the downstream protein CBL-interacting protein kinase (CIPK). CBL1 and CIPK play crucial roles in the response to environmental stresses such as low K+, osmotic shock, high salt, cold and drought.

Structure of human lanthionine synthetase C-like protein 1 and its interaction with Eps8 and glutathione.

Eukaryotic lanthionine synthetase C-like protein 1 (LanCL1) is homologous to prokaryotic lanthionine cyclases, yet its biochemical functions remain elusive. We report the crystal structures of human LanCL1, both free of and complexed with glutathione, revealing glutathione binding to a zinc ion at the putative active site formed by conserved GxxG motifs. We also demonstrate by in vitro affinity analysis that LanCL1 binds specifically to the SH3 domain of a signaling protein, Eps8.

Crystal structure of the complex between Pseudomonas effector AvrPtoB and the tomato Pto kinase reveals both a shared and a unique interface compared with AvrPto-Pto.

Resistance to bacterial speck disease in tomato (Solanum lycopersicum) is activated upon recognition by the host Pto kinase of either one of two sequence-unrelated effector proteins, AvrPto or AvrPtoB, from Pseudomonas syringae pv tomato (Pst). Pto induces Pst immunity by acting in concert with the Prf protein. The recently reported structure of the AvrPto-Pto complex revealed that interaction of AvrPto with Pto appears to relieve an inhibitory effect of Pto, allowing Pto to activate Prf.

Cloning, expression, purification, characterization, crystallization and x-ray diffraction of bifunctional pyrimidine deaminase/reductase from Shigella flexneri 2a.

Bifunctional pyrimidine deaminase/reductase (RibD) plays an important role during riboflavin biosynthesis in many microorganisms. The 40.4 kDa RibD from Shigella flexneri 2a has been cloned, expressed, purified and characterized.

Ca2+ binding effects on the C2 domain conformation of human cytosolic phospholipase A2.

It has been reported that the cooperative binding of calcium ions indicated a local conformational change of the human cytosolic phospholipase A2 (cPLA2) C2 domain (Nalefski et al., (1997) Biochemistry 36, 12011-12018). However its structural evidence is less known (Malmberg et al.

The space experiment of protein crystallization aboard the Chinese spacecraft SZ-3.

Using new flight hardware, a Chinese mission of space protein crystallization has been performed aboard the Chinese spacecraft SZ-3. Preliminary analyses of the experimental results have shown that a few proteins produced better crystals in space. At least, the crystals of cytochrome b5 mutant could diffract X-ray beyond the highest resolution reported so far for the same kind of crystals.