A structural investigation of novel fungal polyglycine hydrolases

Polyglycine hydrolases (PGH) are a family of fungal proteases that are known to cleave the polyglycine linker of Zea mays chitinase, ChitA, thwarting one mechanism of plant defense against fungal infection. Previously, little was known at the atomic level about the interaction between these proteases and their target. There has been limited biochemical characterization and no structural characterization of this family of proteases. In this work, we analyze the atomic structure of one of these polyglycine hydrolases, Fvan-cmp. The structure was solved by X-ray crystallography using a de novo RoseTTAFold model. We report models for the other identified polyglycine hydrolases utilizing the previously determined structure, as well as insights into features likely involved in the catalytic mechanism. The PGH structural characterization identified a two-domain structure, simply named N- and C- domain. The N-domain is a novel tertiary fold found throughout all kingdoms but functionally unidentified. The C-domain shares structural similarities with Class C β-lactamases including the conserved active site motifs and catalytic residues. Utilizing a combination of in vitro and in silico methods, we propose a PGH-ChitA complex model that is supported by previous understanding of PGHs and the structural data. Throughout this work, we discuss the merits and limitations of current in silico methods with a focus on de novo protein modelling and protein-protein docking methods

Human genomics and preparedness for infectious threats

Public health preparedness requires effective surveillance of and rapid response to infectious disease outbreaks. Inclusion of research activities within the outbreak setting provides important opportunities to maximize limited resources, to enhance gains in scientific knowledge, and ultimately to increase levels of preparedness. With rapid advances in laboratory technologies, banking and analysis of human genomic specimens can be conducted as part of public health investigations, enabling valuable research well into the future

Trends in Population-Based Studies of Human Genetics in Infectious Diseases

Pathogen genetics is already a mainstay of public health investigation and control efforts; now advances in technology make it possible to investigate the role of human genetic variation in the epidemiology of infectious diseases. To describe trends in this field, we analyzed articles that were published from 2001 through 2010 and indexed by the HuGE Navigator, a curated online database of PubMed abstracts in human genome epidemiology. We extracted the principal findings from all meta-analyses and genome-wide association studies (GWAS) with an infectious disease-related outcome. Finally, we compared the representation of diseases in HuGE Navigator with their contributions to morbidity worldwide. We identified 3,730 articles on infectious diseases, including 27 meta-analyses and 23 GWAS. The number published each year increased from 148 in 2001 to 543 in 2010 but remained a small fraction (about 7%) of all studies in human genome epidemiology. Most articles were by authors from developed countries, but the percentage by authors from resource-limited countries increased from 9% to 25% during the period studied. The most commonly studied diseases were HIV/AIDS, tuberculosis, hepatitis B infection, hepatitis C infection, sepsis, and malaria. As genomic research methods become more affordable and accessible, population-based research on infectious diseases will be able to examine the role of variation in human as well as pathogen genomes. This approach offers new opportunities for understanding infectious disease susceptibility, severity, treatment, control, and prevention

Influence of Familial Risk on Diabetes Risk–Reducing Behaviors Among U.S. Adults Without Diabetes

OBJECTIVE: To test the association of family history of diabetes with the adoption of diabetes risk–reducing behaviors and whether this association is strengthened by physician advice or commonly known factors associated with diabetes risk. RESEARCH DESIGN AND METHODS: We used cross-sectional data from the 2005–2008 National Health and Nutrition Examination Survey (NHANES) to examine the effects of family history of diabetes on the adoption of selected risk-reducing behaviors in 8,598 adults (aged ≥20 years) without diabetes. We used multiple logistic regression to model three risk reduction behaviors (controlling or losing weight, increasing physical activity, and reducing the amount of dietary fat or calories) with family history of diabetes. RESULTS: Overall, 36.2% of U.S. adults without diabetes had a family history of diabetes. Among them, ~39.8% reported receiving advice from a physician during the past year regarding any of the three selected behaviors compared with 29.2% of participants with no family history (P < 0.01). In univariate analysis, adults with a family history of diabetes were more likely to perform these risk-reducing behaviors compared with adults without a family history. Physician advice was strongly associated with each of the behavioral changes (P < 0.01), and this did not differ by family history of diabetes. CONCLUSIONS: Familial risk for diabetes and physician advice both independently influence the adoption of diabetes risk–reducing behaviors. However, fewer than half of participants with familial risk reported receiving physician advice for adopting these behaviors

Race-Ethnic Differences in the Association of Genetic Loci with HbA1c levels and Mortality in U.S. Adults: The Third National Health and Nutrition Examination Survey (NHANES III)

Background: Hemoglobin A1c (HbA1c) levels diagnose diabetes, predict mortality and are associated with ten single nucleotide polymorphisms (SNPs) in white individuals. Genetic associations in other race groups are not known. We tested the hypotheses that there is race-ethnic variation in 1) HbA1c-associated risk allele frequencies (RAFs) for SNPs near SPTA1, HFE, ANK1, HK1, ATP11A, FN3K, TMPRSS6, G6PC2, GCK, MTNR1B; 2) association of SNPs with HbA1c and 3) association of SNPs with mortality. Methods We studied 3,041 non-diabetic individuals in the NHANES (National Health and Nutrition Examination Survey) III. We stratified the analysis by race/ethnicity (NHW: non-Hispanic white; NHB: non-Hispanic black; MA: Mexican American) to calculate RAF, calculated a genotype score by adding risk SNPs, and tested associations with SNPs and the genotype score using an additive genetic model, with type 1 error = 0.05. Results: RAFs varied widely and at six loci race-ethnic differences in RAF were significant (p < 0.0002), with NHB usually the most divergent. For instance, at ATP11A, the SNP RAF was 54% in NHB, 18% in MA and 14% in NHW (p < .0001). The mean genotype score differed by race-ethnicity (NHW: 10.4, NHB: 11.0, MA: 10.7, p < .0001), and was associated with increase in HbA1c in NHW (β = 0.012 HbA1c increase per risk allele, p = 0.04) and MA (β = 0.021, p = 0.005) but not NHB (β = 0.007, p = 0.39). The genotype score was not associated with mortality in any group (NHW: OR (per risk allele increase in mortality) = 1.07, p = 0.09; NHB: OR = 1.04, p = 0.39; MA: OR = 1.03, p = 0.71). Conclusion: At many HbA1c loci in NHANES III there is substantial RAF race-ethnic heterogeneity. The combined impact of common HbA1c-associated variants on HbA1c levels varied by race-ethnicity, but did not influence mortality

Current Priorities for Public Health Practice in Addressing the Role of Human Genomics in Improving Population Health

In spite of accelerating human genome discoveries in a wide variety of diseases of public health significance, the promise of personalized health care and disease prevention based on genomics has lagged behind. In a time of limited resources, public health agencies must continue to focus on implementing programs that can improve health and prevent disease now. Nevertheless, public health has an important and assertive leadership role in addressing the promise and pitfalls of human genomics for population health. Such efforts are needed not only to implement what is known in genomics to improve health but also to reduce potential harm and create the infrastructure needed to derive health benefits in the future

Multi-Nation WPT Demonstration Experiments

A project originating with Georgia Institute of Technology is described in which the International Space Station (ISS) serves as an experimental platform for the relay of energy from space to earth. The multi-nation test will feature the transmission of small amounts of solar-generated electric power from the ISS using millimeter waves, for the purposes of collecting atmospheric propagation data and testing technologies for power beaming, aiming, and reception. This initiative represents an early first-step towards installation of a global Space Solar Power Grid emphasizing international collaboration, synergy with the terrestrial energy industry and with retail power beaming markets. The technical paper on which this visualization is based is listed in References below. Advisors: Prof. N. Komerath, Prof. D. Flournoy, Kyle Perkins (Designer) Five-Nation - Broadband from Space Journal on Vimeo