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Molina de Aragón, Spain

Hurtado-Guerrero R.,Fundacion ARAID | Hurtado-Guerrero R.,University of Zaragoza
Biochemical Society Transactions | Year: 2016

Protein O-GalNAcylation is an abundant post-translational modification and predicted to occur in over 80 % of the proteins passing through the Golgi apparatus. This modification is driven by 20 polypeptide GaINAc (N-acetylgalactosamine)-transferases (GalNAc-Ts), which are unique in that they possess both catalytic and lectin domains. The peptide substrate specificities of GalNAc-Ts are still poorly defined and our understanding of the sequence and structural features that direct O-glycosylation of proteins is limited. Part of this may be attributed to the complex regulation by coordinated action of multiple GalNAc-T isoforms, and part of this may also be attributed to the two functional domains of GalNAc-Ts that both seems to be involved in directing the substrate specificities. Recent studies have resulted in 3D structures of GalNAc-Ts and determination of the reaction mechanism of this family of enzymes. Key advances include the trapping of binary/ternary complexes in combination with computational simulations and AFM/small-SAXS experiments, which have allowed for the dissection of the reaction coordinates and the mechanism by which the lectin domains modulate the glycosylation. These studies not only broaden our knowledge of the modes-of-action of this family of enzymes but also open up potential avenues for the rational design of effective and selective inhibitors of O-glycosylation. © 2016 Authors; published by Portland Press Limited. Source

Hurtado-Guerrero R.,Fundacion ARAID | Hurtado-Guerrero R.,University of Zaragoza | Davies G.J.,University of York
Current Opinion in Chemical Biology | Year: 2012

Enzymatic glycosylation of proteins, a post-transitional modification of great significance, is carried out by diverse glycosyltransferases (GTs) that harness activated sugar donors, typically nucleotide or lipid-phosphate linked species. Recent work has seen a major increase in the study of the 3D structure and reaction mechanism of these enzymes. Key advances include the dissection of the classical O-glycosylating and N-glycosylating apparatus, revealing unusual folds and hitherto unconsidered chemical mechanisms for acceptor activation. There has been considerable success in the application of kinetic isotope effects and quantum simulations to address the controversial issue of the reaction mechanism of retaining GTs. New roles for old modifications, exemplified by potential epigenetic roles for glycosylation, have been discovered and there has also been a plethora of studies into important mammalian glycosylations that play key roles in cellular biology, opening up new targets for chemical intervention approaches. © 2012 Elsevier Ltd. Source

Sanz A.,CSIC - Centro de Investigacion y Tecnologia Agroalimentaria | Calvo J.H.,Fundacion ARAID | Marti J.I.,CSIC - Centro de Investigacion y Tecnologia Agroalimentaria | Alabart J.L.,CSIC - Centro de Investigacion y Tecnologia Agroalimentaria | And 3 more authors.
Archivos de Zootecnia | Year: 2011

This work aims to present the research activities in the Churra Tensina sheep breed, raised on the mountain area of Huesca Pyrenees. The population structure was prospected and the farming system was characterized through surveys to farmers. The animal morphology was studied through zoometric measurements and phaneroptic characters assessment of the individuals belonging to the breeders' Association (ATURA), showing a mediolineous, dolicocephalous and eumetric breed. The productive and reproductive parameters were analysed, and the commercial value of the suckling, light and heavy lamb categories was confirmed. The genetic studies showed that Churra Tensina is an homogeneous breed, with high genetic variability and low inbreeding. This breed was self-genetic differentiated, and has no crossbreeding with other Churro group populations. Finally, semen and embryos banks were established, being the different Scrapie resistance genotypes represented. The increasing census evolution in the past 10 years and the observed commercial viability assure the long term maintenance of this breed in their original location. Source

Bryson J.F.J.,University of Cambridge | Herrero-Albillos J.,Fundacion ARAID | Herrero-Albillos J.,Centro Universitario Of La Defensa | Herrero-Albillos J.,University of Zaragoza | And 6 more authors.
Earth and Planetary Science Letters | Year: 2014

X-ray photoemission electron microscopy (XPEEM) enables natural remanent magnetisation to be imaged with ~30nm resolution across a field of view of 5-20 μm. The method is applied to structural features typical of the Widmanstätten microstructure (kamacite - tetrataenite rim - cloudy zone - plessite) in the Tazewell IIICD iron meteorite. Kamacite lamellae and the tetrataenite rim are multidomain, whereas plessite consists of laths of different phases displaying a range of stable magnetisation directions. The cloudy zone (CZ) displays a complex interlocking domain pattern resulting from nanoscale islands of tetrataenite with easy axes distributed along three possible crystallographic directions. Quantitative analysis of the coarse and intermediate CZ was achieved using a combination of image simulations and histogram profile matching. Remanence information was extracted from individual regions of interest ~400nm wide, demonstrating for the first time the capability of XPEEM to perform quantitative paleomagnetic analysis at sub-micron length scales. The three tetrataenite easy axis orientations occur with equal probability in the coarse and intermediate CZ, suggesting that spinodal decomposition in these regions was not strongly influenced by internal interaction fields, and that they are suitable candidates for future paleomagnetic studies. The fine CZ shows a strong dominance of one easy axis. This effect is attributed to island-island exchange interactions that render the fine CZ unsuitable for paleomagnetic study. Variations in the relative strength (proportion of dominant easy axis) and direction (direction of dominant easy axis) of a paleomagnetic field can be resolved from different regions of the CZ using XPEEM, raising the prospect of obtaining a time-resolved measurement of the active dynamo period in meteorites originating from the upper unmelted regions of differentiated asteroids (e.g. chondrites, pallasites, mesosiderites). © 2014. Source

Tondo M.L.,National University of Rosario | Hurtado-Guerrero R.,Fundacion ARAID | Hurtado-Guerrero R.,University of Zaragoza | Ceccarelli E.A.,National University of Rosario | And 3 more authors.
BioMed Research International | Year: 2013

We have solved the structure of ferredoxin-NADP(H) reductase, FPR, from the plant pathogen Xanthomonas axonopodis pv. citri, responsible for citrus canker, at a resolution of 1.5 Å. This structure reveals differences in the mobility of specific loops when compared to other FPRs, probably unrelated to the hydride transfer process, which contributes to explaining the structural and functional divergence between the subclass I FPRs. Interactions of the C-terminus of the enzyme with the phosphoadenosine of the cofactor FAD limit its mobility, thus affecting the entrance of nicotinamide into the active site. This structure opens the possibility of rationally designing drugs against the X. axonopodis pv. citri phytopathogen. © 2013 María Laura Tondo et al. Source

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