Home About us Contact
|
Home About us Contact | ||
|
|
||
Selenomethionine Derivative (selenomethionine + derivative)
Selected AbstractsSynthesis of Selenocysteine and Selenomethionine Derivatives from Sulfur-Containing Amino AcidsCHEMISTRY & BIODIVERSITY, Issue 3 2008Michio Iwaoka Abstract Selenium-containing amino acids have attracted increasing interest from view points of the importance as active centers of several selenoenzymes, the biological synthesis, the metabolism, and the use for structure determination of proteins. In this article, our recent progresses in the transformation from sulfur-containing amino acids to selenocysteine (SeCys) and selenomethionine (SeMet) derivatives are reviewed along with the surveys of general organic methodologies for the synthesis of SeCys and SeMet derivatives in the literature. The S,Se modification (i.e., the chemical atomic mutation) would be a useful approach to peptide synthesis involving selenoamino acid residues. [source] Use of novel selenomethionine-resistant yeast to produce selenomethionyl protein suitable for structural analysisFEMS YEAST RESEARCH, Issue 3 2009Toshihiko Kitajima Abstract Yeast is widely used to determine the tertiary structure of eukaryotic proteins, because of its ability to undergo post-translational modifications such as glycosylation. A mutant lacking S -adenosylmethionine synthesis has been reported as a suitable host for producing selenomethionine derivatives, which can help solve phase problems in protein crystallography. However, the mutant required external addition of S -adenosylmethionine for cell proliferation. Here, a selenomethionine-resistant Pichia pastoris mutant that showed S -adenosylmethionine autotrophy was isolated. Human lysozyme expressed by the mutant under the control of constitutive promoter contained selenomethionine at 65% occupancy, sufficient for use as a selenomethionine derivative for single-wavelength anomalous dispersion phasing. [source] Novel structural features in the GMC family of oxidoreductases revealed by the crystal structure of fungal aryl-alcohol oxidaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2009Israel S. Fernández Lignin biodegradation, a key step in carbon recycling in land ecosystems, is carried out by white-rot fungi through an H2O2 -dependent process defined as enzymatic combustion. Pleurotus eryngii is a selective lignin-degrading fungus that produces H2O2 during redox cycling of p -anisylic compounds involving the secreted flavoenzyme aryl-alcohol oxidase (AAO). Here, the 2.4,Å resolution X-ray crystal structure of this oxidoreductase, which catalyzes dehydrogenation reactions on various primary polyunsaturated alcohols, yielding the corresponding aldehydes, is reported. The AAO crystal structure was solved by single-wavelength anomalous diffraction of a selenomethionine derivative obtained by Escherichia coli expression and in vitro folding. This monomeric enzyme is composed of two domains, the overall folding of which places it into the GMC (glucose,methanol,choline oxidase) oxidoreductase family, and a noncovalently bound FAD cofactor. However, two additional structural elements exist in the surroundings of its active site that modulate the access of substrates; these are absent in the structure of the model GMC oxidoreductase glucose oxidase. The folding of these novel elements gives rise to a funnel-like hydrophobic channel that connects the solvent region to the buried active-site cavity of AAO. This putative active-site cavity is located in front of the re side of the FAD isoalloxazine ring and near two histidines (His502 and His546) that could contribute to alcohol activation as catalytic bases. Moreover, three aromatic side chains from two phenylalanines (Phe397 and Phe502) and one tyrosine (Tyr92) at the inner region of the channel form an aromatic gate that may regulate the access of the enzyme substrates to the active site as well as contribute to the recognition of the alcohols that can effectively be oxidized by AAO. [source] Crystallization and preliminary X-ray studies of the glutaredoxin from poplar in complex with glutathioneACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2003Katia D'Ambrosio A monocysteinic mutant of poplar glutaredoxin (C30S) has been overproduced and purified. The protein has been crystallized in complex with glutathione using the hanging-drop vapour-diffusion technique in the presence of PEG 4000 as a precipitating agent. A native data set was collected at 1.55,Å resolution. The crystals belong to space group P212121, with unit-cell parameters a = 45.7, b = 49.1, c = 104.8,Å. Isomorphous crystals of a selenomethionine derivative were grown under the same conditions. Three data sets were collected at 1.73,Å using the FIP synchrotron beamline at the ESRF. The positions of the Se atoms were determined and model rebuilding and refinement are in progress. [source] Crystallization and preliminary crystallographic studies of Mycobacterium tuberculosis DNA gyrase B C-terminal domain, part of the enzyme reaction coreACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2009Guangsen Fu DNA gyrase subunit B C-terminal domain (GyrB-CTD) is a functional module of DNA gyrase which participates in forming the core of DNA gyrase and plays critical roles in G-segment binding and T-segment loading and passage. Here, the purification, crystallization and preliminary X-ray crystallographic studies of GyrB-CTD from Mycobacterium tuberculosis H37Rv are reported. Diffraction data were collected from crystals of native GyrB-CTD and its selenomethionine derivative to resolutions of 2.8 and 3.0,Å, respectively. These crystals belonged to space group P212121 with similar unit-cell parameters. The native protein crystals had unit-cell parameters a = 52.831, b = 52.763, c = 192.579,Å. [source] Purification, crystallization and preliminary X-ray diffraction analysis of human Gadd45,ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2008Wenzheng Zhang Gadd45, MyD118 and CR6 (also termed Gadd45,, Gadd45, and Gadd45,, respectively) comprise a family of proteins that play important roles in negative growth control, maintenance of genomic stability, DNA repair, cell-cycle control and apoptosis. Recombinant human Gadd45, and its selenomethionine derivative were expressed in an Escherichia coli expression system and purified; they were then crystallized using the hanging-drop vapour-diffusion method. Diffraction-quality crystals were grown at 291,K using PEG 3350 as precipitant. Using synchrotron radiation, the best diffraction data were collected to 2.3,Å resolution for native crystals at 100,K; selenomethionyl derivative data were collected to 3.3,Å resolution. All the crystals belonged to space group I213, with approximate unit-cell parameters a = b = c = 126,Å. [source] Expression, purification, crystallization and preliminary X-ray crystallographic analysis of a resuscitation-promoting factor from Mycobacterium tuberculosisACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 10 2007Alessia Ruggiero The resuscitation-promoting factor RpfB, the most complex of the five resuscitation-promoting factors produced by M. tuberculosis, is devoted to bacterial reactivation from the dormant state. RpfB consists of 362 residues predicted to form five domains. An RpfB fragment containing the protein catalytic domain and a G5 domain has been successfully crystallized using vapour-diffusion methods. This is the first crystallographic study of a resuscitation-promoting factor. Crystals of this protein belong to space group I422, with unit-cell parameters a = 97.63, b = 97.63, c = 114.87,Å. Diffraction data have also been collected from a selenomethionine derivative at 2.9,Å resolution. Model building using the phases derived from the multiwavelength anomalous dispersion experiment is in progress. [source] Structure of the ThDP-dependent enzyme benzaldehyde lyase refined to 1.65,Å resolutionACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2007Andy Maraite Benzaldehyde lyase (BAL; EC 4.1.2.38) is a thiamine diphosphate (ThDP) dependent enzyme that catalyses the enantioselective carboligation of two molecules of benzaldehyde to form (R)-benzoin. BAL has hence aroused interest for its potential in the industrial synthesis of optically active benzoins and derivatives. The structure of BAL was previously solved to a resolution of 2.6,Å using MAD experiments on a selenomethionine derivative [Mosbacher et al. (2005), FEBS J.272, 6067,6076]. In this communication of parallel studies, BAL was crystallized in an alternative space group (P212121) and its structure refined to a resolution of 1.65,Å, allowing detailed observation of the water structure, active-site interactions with ThDP and also the electron density for the co-solvent 2-methyl-2,4-pentanediol (MPD) at hydrophobic patches of the enzyme surface. [source] Crystallization and preliminary X-ray crystallographic analysis of the Sulfolobus solfataricus nucleotide-exchange factor 1,ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2005Paolo Arcari The nucleotide-exchange factor isolated from the hyperthermophilic archaeon Sulfolobus solfataricus (SsEF-1,) consists of 90 residues and differs from eukaryal EF-1,s. The protein has been successfully crystallized using either microbatch-under-oil or vapour-diffusion methods. Crystals of native SsEF-1, diffract to 1.97,Å resolution and belong to space group P21212, with unit-cell parameters a = 106.46, b = 54.87, c = 44.03,Å. Diffraction data have also been collected from a selenomethionine derivative of SsEF-1, at 1.83,Å resolution. Model building using the phases derived from the MAD experiment is in progress. [source] Use of novel selenomethionine-resistant yeast to produce selenomethionyl protein suitable for structural analysisFEMS YEAST RESEARCH, Issue 3 2009Toshihiko Kitajima Abstract Yeast is widely used to determine the tertiary structure of eukaryotic proteins, because of its ability to undergo post-translational modifications such as glycosylation. A mutant lacking S -adenosylmethionine synthesis has been reported as a suitable host for producing selenomethionine derivatives, which can help solve phase problems in protein crystallography. However, the mutant required external addition of S -adenosylmethionine for cell proliferation. Here, a selenomethionine-resistant Pichia pastoris mutant that showed S -adenosylmethionine autotrophy was isolated. Human lysozyme expressed by the mutant under the control of constitutive promoter contained selenomethionine at 65% occupancy, sufficient for use as a selenomethionine derivative for single-wavelength anomalous dispersion phasing. [source] Crystallization and preliminary crystallographic analysis of recombinant VSP1 from Arabidopsis thalianaACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2010Zhu-Bing Shi VSP1 is a defence protein in Arabidopsis thaliana that may also be involved in control of plant development. The recombinant protein has been overexpressed in Escherichia coli, purified and crystallized using the sitting-drop vapour-diffusion method. The crystal diffracted to 1.9,Å resolution and a complete X-ray data set was collected at 100,K using Cu,K, radiation from a rotating-anode X-ray source. The crystals belonged to space group C2. As there are no related structures that could be used as a search model for molecular replacement, work is in progress on experimental phasing using heavy-atom derivatives and selenomethionine derivatives. [source] Crystallization and preliminary X-ray diffraction analysis of the P3 RNA domain of yeast ribonuclease MRP in a complex with RNase P/MRP protein components Pop6 and Pop7ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2010Anna Perederina Eukaryotic ribonucleases P and MRP are closely related RNA-based enzymes which contain a catalytic RNA component and several protein subunits. The roles of the protein subunits in the structure and function of eukaryotic ribonucleases P and MRP are not clear. Crystals of a complex that included a circularly permuted 46-nucleotide-long P3 domain of the RNA component of Saccharomyces cerevisiae ribonuclease MRP and selenomethionine derivatives of the shared ribonuclease P/MRP protein components Pop6 (18.2,kDa) and Pop7 (15.8,kDa) were obtained using the sitting-drop vapour-diffusion method. The crystals belonged to space group P4222 (unit-cell parameters a = b = 127.2, c = 76.8,Å, , = , = , = 90°) and diffracted to 3.25,Å resolution. [source] | ||||||||||