Structural transitions in full-length human prion protein detected by xenon as probe and spin labeling of the N-terminal domain

Fatal neurodegenerative disorders termed transmissible spongiform encephalopathies (TSEs) are associated with the accumulation of fibrils of misfolded prion protein PrP. The noble gas xenon accommodates into four transiently enlarged hydrophobic cavities located in the well-folded core of human PrP(23-230) as detected by [H-1, N-15]-HSQC spectroscopy. In thermal equilibrium a fifth xenon binding site is formed transiently by amino acids A120 to L125 of the presumably disordered N-terminal domain and by amino acids K185 to T193 of the well-folded domain. Xenon bound PrP was modelled by restraint molecular dynamics. The individual microscopic and macroscopic dissociation constants could be derived by fitting the data to a model including a dynamic opening and closing of the cavities. As observed earlier by high pressure NMR spectroscopy xenon binding influences also other amino acids all over the N-terminal domain including residues of the AGAAAAGA motif indicating a structural coupling between the N-terminal domain and the core domain. This is in agreement with spin labelling experiments at positions 93 or 107 that show a transient interaction between the N-terminus and the start of helix 2 and the end of helix 3 of the core domain similar to that observed earlier by Zn2+-binding to the octarepeat motif

Training Manual on "Know Your Marine Biodiversity and Environment (MarBiE 2)" Taxonomy of Marine Organisms

Sustainable fisheries management aims to protect fishery resources to ensure the long-term viability of fish stocks and marine ecosystems. It combines theoretical disciplines, like population dynamics, with practical strategies, like avoiding overfishing and curbing illegal fishing practices. Correct taxonomy and systematics tools permit the classification of practically all fish species. This capacity is of particular value for fisheries management biological and ecological research as well as to issues related to fisheries products for human consumption. However, its usefulness is hindered by the lack of expertise in this area and the decrease in the number of taxonomists. Specimens have to be identified at species level using standard morphometric and meristic procedures applied by taxonomists. With sustainability being the critical issue of the hour, developing a younger breed of qualified taxonomists in the different marine realm is of outmost importance. It is physically difficult to identify and collect data on every organism in an ecosystem; therefore, taxonomic studies focus exclusively on specific taxonomic groups, which highlights their significance. The application of contemporary techniques will enhance our understanding of evolutionary linkages. This can entail educating a new generation of specialists on the systematics of the relevant group or persuading more experienced experts to write assessments of the group. The credibility of species occurrence records from current databases and literature needs to be thoroughly evaluated

Elasmobranch conservation, challenges and management strategy in India: recommendations from a national consultative meeting

Historically, India has been projected as one of the major elasmobranch fishing nations in the world. However, management and conservation efforts are not commensurate with this trend. Along with the Wildlife (Protection) Act, 1972, several generic conservation measures are in place at the regional/local level. But India is still a long way from meeting global conservation commitments. We present here the status of elasmobranch management and conservation in India, with the specific objec-tive of identifying the gaps in the existing set-up. We also present recommendations based on a national consultative workshop held at the Central Marine Fisheries Research Institute, Kochi, in February 2020. We recommend the implementation of a National Plan of Action (NPOA-Sharks) and more in-clusive governance and policymaking for elasmobranch conservation in India