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Developments in quantum computing may jeopardize the security of internet voting. Such developments could compromise important electoral requirements, including integrity, eligibility, or the secrecy of the vote. Even the contents of a vote cast online today, when quantum computers are not yet known to be available, could be revealed tomorrow. Countries are already working on a post-quantum setting, but elections seem to remain an exception. In this paper, we explore the existing strategies to mitigate the quantum threat or their lack thereof, as well as the views of different stakeholders on these matters. To do so, we have conducted a mix of desk research as well as interviews with 24 experts in different fields, from electoral administrations to cybersecurity agencies, vendors, and academia. We assess their perceptions about quantum computing, its impact on internet voting, and on transitioning towards quantum-resistant cryptography, as well as on interagency cooperation and trust issues. Whereas we initially assumed that elections were an exception in regards to the transition towards post-quantum cryptography, this research shows that the electoral field is neither alone nor the most adequate one to start the implementation of this kind of cryptography.

El pdf es el manuscrito de autor (PMCID: PMC3077575).-- et al. ; Metallopeptidases (MPs) are among virulence factors secreted by pathogenic bacteria at the site of infection. One such pathogen is Tannerella forsythia, a member of the microbial consortium that causes peridontitis, arguably the most prevalent infective chronic inflammatory disease known to mankind. The only reported MP secreted by T. forsythia is karilysin, a 52 kDa multidomain protein comprising a central 18 kDa catalytic domain (CD), termed Kly18, flanked by domains unrelated to any known protein. We analysed the 3D structure of Kly18 in the absence and presence of Mg2+ or Ca2+, which are required for function and stability, and found that it evidences most of the structural features characteristic of the CDs of mammalian matrix metalloproteinases (MMPs). Unexpectedly, a peptide was bound to the active-site cleft of Kly18 mimicking a left-behind cleavage product, which revealed that the specificity pocket accommodates bulky hydrophobic side-chains of substrates as in mammalian MMPs. In addition, Kly18 displayed a unique Mg2+ or Ca2+ binding site and two flexible segments that could play a role in substrate binding. Phylogenetic and sequence similarity studies revealed that Kly18 is evolutionarily much closer to winged-insect and mammalian MMPs than to potential bacterial counterparts found by genomic sequencing projects. Therefore, we conclude that this first structurally characterized non-mammalian MMP is a xenologue co-opted through horizontal gene transfer during the intimate coexistence between T. forsythia and humans or other animals, in a very rare case of gene shuffling from eukaryotes to prokaryotes. Subsequently, this protein would have evolved in a bacterial environment to give rise to full-length karilysin that is furnished with unique flanking domains that do not conform to the general multidomain architecture of animal MMPs. ; This study was in part supported by grants from European, Spanish, Polish and Catalan public agencies (FP7-HEALTH-F3-2009-223101 'AntiPathoGN', FP7- HEALTH-2010-261460 'Gums&Joints', BIO2008-04080-E, BIO2009-10334, CSD2006-00015, PSE-010000-2009-8, 2009SGR1036 and MNiSzW 1642/B/P01/2008/35) and by grant DE 09761 from the National Institutes of Health, USA. The Faculty of Biochemistry, Biophysics and Biotechnology of the Jagiellonian University is a beneficent of the structural funds from the European Union (Grant No.: POIG.02.01.00-12-064/08 – 'Molecular biotechnology for health'). ; Peer Reviewed

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 Reviewed