Search results for "SIDA"
showing 10 items of 1584 documents
Structures of Alkaloid Biosynthetic Glucosidases Decode Substrate Specificity
2011
Two similar enzymes with different biosynthetic function in one species have evolved to catalyze two distinct reactions. X-ray structures of both enzymes help reveal their most important differences. The Rauvolfia alkaloid biosynthetic network harbors two O-glucosidases: raucaffricine glucosidase (RG), which hydrolyses raucaffricine to an intermediate downstream in the ajmaline pathway, and strictosidine glucosidase (SG), which operates upstream. RG converts strictosidine, the substrate of SG, but SG does not accept raucaffricine. Now elucidation of crystal structures of RG, inactive RG-E186Q mutant, and its complexes with ligands dihydro-raucaffricine and secologanin reveals that it is the…
Ligand structures of synthetic deoxa-pyranosylamines with raucaffricine and strictosidine glucosidases provide structural insights into their binding…
2014
Insight into the structure and inhibition mechanism of O-β-d-glucosidases by deoxa-pyranosylamine type inhibitors is provided by X-ray analysis of complexes between raucaffricine and strictosidine glucosidases and N-(cyclohexylmethyl)-, N-(cyclohexyl)- and N-(bromobenzyl)-β-d-gluco-1,5-deoxa-pyranosylamine. All inhibitors anchored exclusively in the catalytic active site by competition with appropriate enzyme substrates. Thus facilitated prospective elucidation of the binding networks with residues located at <3.9 A distance will enable the development of potent inhibitors suitable for the production of valuable alkaloid glucosides, raucaffricine and strictosidine, by means of synthesis in …
Molecular Architecture of Strictosidine Glucosidase: The Gateway to the Biosynthesis of the Monoterpenoid Indole Alkaloid Family[W]
2007
Abstract Strictosidine β-d-glucosidase (SG) follows strictosidine synthase (STR1) in the production of the reactive intermediate required for the formation of the large family of monoterpenoid indole alkaloids in plants. This family is composed of ∼2000 structurally diverse compounds. SG plays an important role in the plant cell by activating the glucoside strictosidine and allowing it to enter the multiple indole alkaloid pathways. Here, we report detailed three-dimensional information describing both native SG and the complex of its inactive mutant Glu207Gln with the substrate strictosidine, thus providing a structural characterization of substrate binding and identifying the amino acids …
Characterization of aCandida albicansgene encoding a putative transcriptional factor required for cell wall integrity
2003
After screening a Candida albicans genome database the product of an open reading frame (ORF) (CA2880) with 49% homology to the product of Saccharomyces cerevisiae YPL133c, a putative transcriptional factor, was identified. The disruption of the C. albicans gene leads to a major sensitivity to calcofluor white and Congo red, a minor sensitivity to sodium dodecyl sulfate, a major resistance to zymolyase, and an alteration of the chemical composition of the cell wall. For these reasons we called it CaCWT1 (for C. albicans cell wall transcription factor). CaCwt1p contains a putative Zn(II) Cys(6) DNA binding domain characteristic of some transcriptional factors and a PAS domain. The CaCWT1 gen…
A multidomain xylanase from a Bacillus sp. with a region homologous to thermostabilizing domains of thermophilic enzymes
1999
The gene xynC encoding xylanase C from Bacillus sp. BP-23 was cloned and expressed in Escherichia coli. The nucleotide sequence of a 3538 bp DNA fragment containing xynC gene was determined, revealing an open reading frame of 3258 bp that encodes a protein of 120,567 Da. A comparison of the deduced amino acid sequence of xylanase C with known beta-glycanase sequences showed that the encoded enzyme is a modular protein containing three different domains. The central region of the enzyme is the catalytic domain, which shows high homology to family 10 xylanases. A domain homologous to family IX cellulose-binding domains is located in the C-terminal region of xylanase C, whilst the N-terminal r…
Listado actualizado y comentado de las babosas terrestres (Mollusca: Gastropoda: Stylommatophora) de la península ibérica y las islas Baleares
2022
En este artículo recopilamos y comentamos la lista de las especies de babosas terrestres (“Pulmonados desnudos”) de la península ibérica (algunas también presentes en el sur de Francia) e islas Baleares, basándonos en una revisión bibliográfica hasta el nivel de especie y en nuestras propias recolecciones. Está formada por 71 especies, de las cuales 34 son endémicas, y de ellas sólo dos de Baleares, pertenecientes a 9 familias y 16 géneros. Realizamos 30 comentarios sobre diversas características morfo-anatómicas de algunos taxones del listado y se discuten algunos aspectos nomenclaturales…
Huntington: hablar inglés o morir
2004
Two new species ofUlota(Orthotrichaceae, Bryopsida) with multicellular spores, from the Hengduan Mountains, Southwestern China
2011
Two new species, Ulota yunnanensis and Ulota gigantospora, are described from Yunnan and Sichuan Provinces, China. Both have multicellular spores, a relatively uncommon character in the genus. Differences between the species include growth form and habit, leaf areolation, capsule shape, peristome structure and ornamentation, operculum shape and colour, as well as vaginula and calyptra hairiness. These characters and those discriminating the new species from other ones with similar spore type are discussed and illustrated.
Gobernación del Mundo: Por qué y para qué
2006
La nueva sociedad contra el viejo Estado
2004
Reseña de dos de los volúmenes del programa "Europa-Mundi", dirigido y coordinado por José Vidal-Beneyto: "La ventana global" (2002), y "Hacia una sociedad civil global" (2003). Además de estos dos volúmenes, se publicó un tercero: "Derechos humanos y diversidad cultural" (2006). Existe un cuarto volumen inédito: "Ciudadanía mundial y poder global".