Crystal structures of β-carboxysome shell protein CcmP: ligand binding correlates with the closed or open central pore.

Cyanobacterial CO2 fixation is promoted by encapsulating and co-localizing the CO2-fixing enzymes within a protein shell, the carboxysome. A key feature of the carboxysome is its ability to control selectively the flux of metabolites in and out of the shell. The β-carboxysome shell protein CcmP has been shown to form a double layer of pseudohexamers with a relatively large central pore (~13 Å diameter), which may allow passage of larger metabolites such as the substrate for CO2 fixation, ribulose 1,5-bisphosphate, through the shell.

Structure of Arabidopsis thaliana Rubisco activase.

The CO2-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is inactivated by the formation of dead-end complexes with inhibitory sugar phosphates. In plants and green algae, the ATP-dependent motor protein Rubisco activase restores catalytic competence by facilitating conformational changes in Rubisco that promote the release of the inhibitory compounds from the active site. Here, the crystal structure of Rubisco activase from Arabidopsis thaliana is presented at 2.

Crystal structure and computational characterization of the lytic polysaccharide monooxygenase GH61D from the Basidiomycota fungus Phanerochaete chrysosporium.

Carbohydrate structures are modified and degraded in the biosphere by a myriad of mostly hydrolytic enzymes. Recently, lytic polysaccharide mono-oxygenases (LPMOs) were discovered as a new class of enzymes for cleavage of recalcitrant polysaccharides that instead employ an oxidative mechanism. LPMOs employ copper as the catalytic metal and are dependent on oxygen and reducing agents for activity.

Fractional factorial approach combining 4 Escherichia coli strains, 3 culture media, 3 expression temperatures and 5 N-terminal fusion tags for screening the soluble expression of recombinant proteins.

Producing recombinant proteins in Escherichia coli (E. coli) is generally performed using a trial and error approach with the different expression variables being tested independently from each other. As a consequence, variable interactions are lost which makes the trial and error approach quite time-consuming.

Design, synthesis, and X-ray crystallographic studies of α-aryl substituted fosmidomycin analogues as inhibitors of Mycobacterium tuberculosis 1-deoxy-D-xylulose 5-phosphate reductoisomerase.

The natural antibiotic fosmidomycin acts via inhibition of 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), an essential enzyme in the non-mevalonate pathway of isoprenoid biosynthesis. Fosmidomycin is active on Mycobacterium tuberculosis DXR (MtDXR), but it lacks antibacterial activity probably because of poor uptake. α-Aryl substituted fosmidomycin analogues have more favorable physicochemical properties and are also more active in inhibiting malaria parasite growth.

Selenomethionine labeling of recombinant proteins.

Selenomethionine incorporation is a standard method for determining the phases in protein crystallography by single- or multiwavelength anomalous dispersion. Recombinant expression of selenomethionine-containing protein in non-auxotrophic Pichia pastoris strains yield an incorporation of about 50%. The expression of a mutated variant of Penicillium minioluteum dextranase in P.

X-ray crystallographic native sulfur SAD structure determination of laminarinase Lam16A from Phanerochaete chrysosporium.

Laminarinase Lam16A from Phanerochaete chrysosporium was recombinantly expressed in Pichia pastoris, crystallized and the structure was solved at 1.34 A resolution using native sulfur SAD X-ray crystallography. It is the first structure of a non-specific 1,3(4)-beta-D-glucanase from glycoside hydrolase family 16 (GH16).

Three-dimensional crystal structure and enzymic characterization of beta-mannanase Man5A from blue mussel Mytilus edulis.

Endo-beta-1,4-d-mannanase is the key depolymerizing enzyme for beta-1,4-mannan polymers present in the cell walls of plants and some algae, as well as in some types of plant seeds. Endo-1,4-beta-mannanase from blue mussel Mytilus edulis (MeMan5A) belongs to the glycoside hydrolase (GH) family 5 enzymes. The MeMan5A structure has been determined to 1.

Crystal structure of Thermobifida fusca endoglucanase Cel6A in complex with substrate and inhibitor: the role of tyrosine Y73 in substrate ring distortion.

Endoglucanase Cel6A from Thermobifida fusca hydrolyzes the beta-1,4 linkages in cellulose at accessible points along the polymer. The structure of the catalytic domain of Cel6A from T. fusca in complex with a nonhydrolysable substrate analogue that acts as an inhibitor, methylcellobiosyl-4-thio-beta-cellobioside (Glc(2)-S-Glc(2)), has been determined to 1.

Structure and function of carbonic anhydrases from Mycobacterium tuberculosis.

Carbonic anhydrases catalyze the reversible hydration of carbon dioxide to form bicarbonate. This activity is universally required for fatty acid biosynthesis as well as for the production of a number of small molecules, pH homeostasis, and other functions. At least three different carbonic anhydrase families are known to exist, of which the alpha-class found in humans has been studied in most detail.

Dextranase from Penicillium minioluteum: reaction course, crystal structure, and product complex.

Dextranase catalyzes the hydrolysis of the alpha-1,6-glycosidic linkage in dextran polymers. The structure of dextranase, Dex49A, from Penicillium minioluteum was solved in the apo-enzyme and product-bound forms. The main domain of the enzyme is a right-handed parallel beta helix, which is connected to a beta sandwich domain at the N terminus.

X-ray structure and ligand binding study of a moth chemosensory protein.

Chemosensory proteins (CSPs) are believed to be involved in chemical communication and perception. Such proteins, of M(r) 13,000, have been isolated from several sensory organs of a wide range of insect species. Several CSPs have been identified in the antennae and proboscis of the moth Mamestra brassicae.

Preparation and crystallization of selenomethionyl dextranase from Penicillium minioluteum expressed in Pichia pastoris.

Dextranase from the fungus Penicillium minioluteum hydrolyses alpha-1,6-glycosidic bonds in dextran polymers. The enzyme has been expressed in Pichia pastoris in the presence of selenomethionine (SeMet). The level of SeMet incorporation was estimated by amino-acid analysis to be 50%.