The outer-membrane export signal of Porphyromonas gingivalis type IX secretion system (T9SS) is a conserved C-terminal β-sandwich domain

Iñaki de Diego et al.In the recently characterized Type IX Secretion System (T9SS), the conserved C-terminal domain (CTD) in secreted proteins functions as an outer membrane translocation signal for export of virulence factors to the cell surface in the Gram-negative Bacteroidetes phylum. In the periodontal pathogen Porphyromonas gingivalis, the CTD is cleaved off by PorU sortase in a sequence-independent manner, and anionic lipopolysaccharide (A-LPS) is attached to many translocated proteins, thus anchoring them to the bacterial surface. Here, we solved the atomic structure of the CTD of gingipain B (RgpB) from P. gingivalis, alone and together with a preceding immunoglobulin-superfamily domain (IgSF). The CTD was found to possess a typical Ig-like fold encompassing seven antiparallel β-strands organized in two β-sheets, packed into a β-sandwich structure that can spontaneously dimerise through C-terminal strand swapping. Small angle X-ray scattering (SAXS) revealed no fixed orientation of the CTD with respect to the IgSF. By introducing insertion or substitution of residues within the inter-domain linker in the native protein, we were able to show that despite the region being unstructured, it nevertheless is resistant to general proteolysis. These data suggest structural motifs located in the two adjacent Ig-like domains dictate the processing of CTDs by the T9SS secretion pathway.This study was financially supported in part by grants from European, US American, Polish, Spanish, and Catalan agencies (UMO-2012/04/A/NZ1/00051, UMO-2012/05/B/NZ6/00581, UMO-2013/08/W/NZ1/00696, UMO-2011/01/D/NZ1/01169, 2975/7.PR/13/2014/2, NIH NIDCR DE09761; FP7-PEOPLE-2011-ITN-290246 “RAPID”; FP7-HEALTH-2012-306029-2 “TRIGGER”; BFU2012-32862; BIO2013-49320-EXP; MDM-2014-0435; 1306/MOB/IV/2015/0 (“Mobilność Plus” MK) and 2014SGR9). The Department of Structural Biology of IBMB is a “María de Maeztu” Unit of Excellence from the Ministry of Economy and Competitiveness. Funding for data collection was provided in part by ESRFPeer Reviewe

Privacy-enhancing distributed protocol for data aggregation based on blockchain and homomorphic encryption

The recent increase in reported incidents of security breaches compromising users' privacy call into question the current centralized model in which third-parties collect and control massive amounts of personal data. Blockchain has demonstrated that trusted and auditable computing is possible using a decentralized network of peers accompanied by a public ledger. Furthermore, Homomorphic Encryption (HE) guarantees confidentiality not only on the computation but also on the transmission, and storage processes. The synergy between Blockchain and HE is rapidly increasing in the computing environment. This research proposes a privacy-enhancing distributed and secure protocol for data aggregation backboned by Blockchain and HE technologies. Blockchain acts as a distributed ledger which facilitates efficient data aggregation through a Smart Contract. On the top, HE will be used for data encryption allowing private aggregation operations. The theoretical description, potential applications, a suggested implementation and a performance analysis are presented to validate the proposed solution.This work has been partially supported by the Basque Country Government under the ELKARTEK program, project TRUSTIND (KK- 2020/00054). It has also been partially supported by the H2020 TERMINET project (GA 957406)

Structure of the catalytic domain of the Tannerella forsythia matrix metallopeptidase karilysin in complex with a tetrapeptidic inhibitor

5 páginas, 1 figura, 1 tabla.-- et al.Karilysin is the only metallopeptidase identified as a virulence factor in the odontopathogen Tannerella forsythia owing to its deleterious effect on the host immune response during bacterial infection. The very close structural and sequence-based similarity of its catalytic domain (Kly18) to matrix metalloproteinases suggests that karilysin was acquired by horizontal gene transfer from an animal host. Previous studies by phage display identified peptides with the consensus sequence XWFPXXXGGG (single-letter amino-acid codes; X represents any residue) as karilysin inhibitors with low-micromolar binding affinities. Subsequent refinement revealed that inhibition comparable to that of longer peptides could be achieved using the tetrapeptide SWFP. To analyze its binding, the high-resolution crystal structure of the complex between Kly18 and SWFP was determined and it was found that the peptide binds to the primed side of the active-site cleft in a substrate-like manner. The catalytic zinc ion is clamped by the α-amino group and the carbonyl O atom of the serine, thus distantly mimicking the general manner of binding of hydroxamate inhibitors to metallopeptidases and contributing, together with three zinc-binding histidines from the protein scaffold, to an octahedral-minus-one metal-coordination sphere. The tryptophan side chain penetrates the deep partially water-filled specificity pocket of Kly18. Together with previous serendipitous product complexes of Kly18, the present results provide the structural determinants of inhibition of karilysin and open the field for the design of novel inhibitory strategies aimed at the treatment of human periodontal disease based on a peptidic hit molecule. © 2013.This study was supported in part by grants from European, American, Polish, Spanish, Danish and Catalan agencies (2012/04/A/NZ1/00051, 2011/03/N/NZ1/00586, 2137/7.PR-EU/2011/2, DE09761, FP7-HEALTH-F3-2009-223101 ‘AntiPathoGN’, FP7-HEALTH-2010-261460 ‘Gums&Joints’, FP7-PEOPLE-2011-ITN-290246 ‘RAPID’, BIO2009-10334, BFU2012-32862, CSD2006-00015, Lundbeck Foundation grant R54-A5291 and Fundació ‘La Marató de TV3’ grants 2009-100732 and 2009SGR1036). The Faculty of Biochemistry, Biophysics and Biotechnology of the Jagiellonian University in Kraków (Poland) is a beneficiary of structural funds from the European Union (grant No POIG.02.01.00-12-064/08 ‘Molecular Biotechnology for Health’).Peer Reviewe

Kinetic analysis of a Cu-based oxygen carrier: Relevance of temperature and oxygen partial pressure on reduction and oxidation reactions rates in Chemical Looping with Oxygen Uncoupling (CLOU)

The kinetic of reduction of CuO to Cu2O with N2+O2 mixtures and the oxidation of Cu2O to CuO with O2 of a Cu-based oxygen carrier for the CLOU process has been determined in a TGA. For kinetic determination, the O2 concentrations were varied between 0 and 9 vol.% for reduction, and between 21 and 1.5 vol.% for oxidation reactions; temperature was varied between 1148 and 1273 K for the reduction and between 1123 and 1273 K for the oxidation. The oxygen carrier showed high reactivity both in oxidation and reduction reactions. The nucleation and nuclei growth model with chemical reaction control properly described the evolution of solids conversion with time. The Langmuir-Hinshelwood model was able to describe the effect of oxygen concentration on reduction and oxidation rates. The reaction order was 0.5 for reduction and 1.2 for the oxidation. The kinetic constant activation energies were 270 kJ mol-1 for the reduction and 32 kJ mol-1 for the oxidation. The kinetic model was used to calculate the solids inventory needed in the fuel reactor for complete combustion of three different rank coals. It was possible to use a low oxygen carrier inventory in the fuel reactor (160 kg/MWth) to supply the oxygen required to full lignite combustion. However, to reach high CO2 capture efficiencies (³95%), oxygen carrier inventories in fuel reactor higher than 600 kg/MWth were needed with the lignite.This work was supported by the European Commission, under the RFCS program (ACCLAIM Project, Contract RFCP-CT-2012-00006), the Spanish Ministry of Science and Innovation (MICINN Project: ENE2011-26354) and the European Union FEDER Funds. I. Adánez-Rubio thanks CSIC for the JAE fellowship co-financed by the European Social Fund.Peer reviewe

A reflective middleware for controlling smart objects from mobile devices

Mobile devices are mainly used for communication, entertainment, and as electronic assistants. However, their increasing computational, storage, communicational and multimedia capabilities make them suitable for previously unexpected scenarios such as Ambient Intelligence (AmI). Thus, mobile devices may be used as intermediaries between us and the smart objects (everyday objects augmented with computational services) in our surroundings. This paper describes the design and implementation of a middleware to transform mobile devices into universal remote controllers of smart objects. 1

Guía para el desarrollo y evaluación continua de las competencias transversales en el Trabajo de Fin de Grado mediante dinámicas colaborativas

Disponible también en EuskaraLa presente publicación es el resultado de la experiencia llevada a cabo en el marco de un Proyecto de Innovación Educativa financiado por el Servicio de Asesoramiento Educativo de la Universidad Pública del País Vasco (UPV/EHU). El proyecto contó con la participación de un equipo docente multidisciplinar integrado por personas con diferentes perfiles (geología, salud pública, tecnología de alimentos, nutrición, bromatología y físico-química) y tuvo como objetivo el desarrollo de una metodología activa aplicarla en la realización del Trabajo Fin de Grado (TFG). Esta asignatura, común a la mayoría de los grados universitarios y que se desarrolla en la etapa previa a la incorporación a la práctica profesional, supone una gran oportunidad para que los futuros egresados profundicen y afiancen las competencias transversales recogidas en los planes de estudio de cada titulación. El desarrollo de la propuesta metodológica tuvo como eje principal fomentar la adquisición de competencias transversales tales como la capacidad de reflexión y crítica, habilidad para la comunicación oral y escrita, capacidad de trabajo en equipo o el manejo adecuado de las fuentes bibliográficas.Servicio de Asesoramiento Educativo de la Universidad del País Vasco (SAE/HELAZ), 6570-Proyecto de Innovación Educativa 2012-2014

Gradu Amaierako Lanean zeharkako gaitasunak lankidetza-dinamiken bidez garatzeko eta era jarraituan ebaluatzeko gida

Gaztelerazko bertsioan ere argitaratua Itzultzailea: Gilen MejutoHezkuntza Berrikuntzarako Proiektu baten barruan burututako esperientziaren emaitza da argitalpen hau. Delako proiektua Euskal Herriko Unibertsitate Publikoaren (UPV/EHU) Hezkuntzarako Laguntza Zerbitzuak finantzatu zuen. Proiektuan, diziplina anitzeko irakasle talde bat aritu zen, hainbat profiletako pertsonek osatutakoa (geologia, osasun publikoa, elikagaien teknologia, nutrizioa, bromatologia eta fisikokimika), eta helburua izan zen metodologia aktibo bat garatzea, gero Gradu Amaierako Lana (GrAL) egiteko prozesuari aplikatzekoa. Irakasgai hau komuna izaten da unibertsitate-gradu gehienetan, eta lanbidean hasi aurreko etapan garatzen da. Gainera, aukera ezin hobea da graduatuko diren pertsonek sakondu eta finkatu ditzaten titulazio bakoitzeko ikasketa-planetan jasotzen diren zeharkako gaitasunak. Proposamen metodologikoa garatzeko orduan, ikasleek zeharkako gaitasunak eskuratzeko prozesua izan zen ardatz nagusia. Hona zeharkako gaitasun horietako batzuk: hausnarketa eta kritika egiteko ahalmena, ahozko eta idatzizko komunikaziorako trebetasuna, taldean lan egiteko ahalmena eta iturri bibliografikoen erabilera egokia.Euskal Herriko Unibertsitateako Hezkuntzarako Laguntza Zerbitzua (SAE-HELAZ), 6570-Hezkuntzaren Berrikuntzarako Proiektua 2012-2014

The outer-membrane export signal of Porphyromonas gingivalis type IX secretion system (T9SS) is a conserved C-terminal \beta-sandwich domain

In the recently characterized Type IX Secretion System (T9SS), the conserved C-terminal domain (CTD) in secreted proteins functions as an outer membrane translocation signal for export of virulence factors to the cell surface in the Gram-negative Bacteroidetes phylum. In the periodontal pathogen Porphyromonas gingivalis, the CTD is cleaved off by PorU sortase in a sequence-independent manner, and anionic lipopolysaccharide (A-LPS) is attached to many translocated proteins, thus anchoring them to the bacterial surface. Here, we solved the atomic structure of the CTD of gingipain B (RgpB) from P. gingivalis, alone and together with a preceding immunoglobulin-superfamily domain (IgSF). The CTD was found to possess a typical Ig-like fold encompassing seven antiparallel β-strands organized in two β-sheets, packed into a β-sandwich structure that can spontaneously dimerise through C-terminal strand swapping. Small angle X-ray scattering (SAXS) revealed no fixed orientation of the CTD with respect to the IgSF. By introducing insertion or substitution of residues within the inter-domain linker in the native protein, we were able to show that despite the region being unstructured, it nevertheless is resistant to general proteolysis. These data suggest structural motifs located in the two adjacent Ig-like domains dictate the processing of CTDs by the T9SS secretion pathway