Structural basis of meiotic telomere attachment to the nuclear envelope by MAJIN-TERB2-TERB1.

Meiotic chromosomes undergo rapid prophase movements, which are thought to facilitate the formation of inter-homologue recombination intermediates that underlie synapsis, crossing over and segregation. The meiotic telomere complex (MAJIN, TERB1, TERB2) tethers telomere ends to the nuclear envelope and transmits cytoskeletal forces via the LINC complex to drive these rapid movements. Here, we report the molecular architecture of the meiotic telomere complex through the crystal structure of MAJIN-TERB2, together with light and X-ray scattering studies of wider complexes. The MAJIN-TERB2 2:2 hetero-tetramer binds strongly to DNA and is tethered through long flexible linkers to the inner nuclear membrane and two TRF1-binding 1:1 TERB2-TERB1 complexes. Our complementary structured illumination microscopy studies and biochemical findings reveal a telomere attachment mechanism in which MAJIN-TERB2-TERB1 recruits telomere-bound TRF1, which is then displaced during pachytene, allowing MAJIN-TERB2-TERB1 to bind telomeric DNA and form a mature attachment plate

Target highlights in CASP13: experimental target structures through the eyes of their authors

The functional and biological significance of selected CASP13 targets are described by the authors of the structures. The structural biologists discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP13 experiment

RepEx: Repeat extractor for biological sequences

Genomic sequences are far from being random but are made up of systematically ordered and information rich patterns. These repeated sequence patterns have been vastly utilized for their fundamental importance in understanding the genome function and organization. To this end, a comprehensive toolkit, RepEx, has been developed which extracts repeat (inverted, everted and mirror) patterns from the given genome sequence(s) without any constraints. The toolkit can also be used to fetch the inverted repeats present in the protein sequence (s). Further, it is capable of extracting exact and degenerate repeats with a user defined spacer intervals. It is remarkably more precise and sensitive when compared to the existing tools. An example with comprehensive case studies and a performance evaluation of the proposed toolkit has been presented to authenticate its efficiency and accuracy. (C) 2013 Elsevier Inc. All rights reserved

Experimental Study on concrete behaviour with Partial Replacement of M-Sand with Unexpanded Perlite

Traditionally, river sand was utilized as fine aggregate in concrete manufacturing. However, due to the ongoing extraction of natural river sand, its availability has become limited. Construction businesses have begun to explore for alternative sustainable resources to use as fine aggregate. Manufactured sand (M- sand), recycled concrete aggregate, crushed granite, rice husk ash, fly ash, and other materials can cause dumpsite and environmental contamination. These materials are viable substitutes for natural river sand as fine aggregate. Unexpanded perlite is also one such material which can be used as a replacement for fine aggregate. Unexpanded Perlite is a natural material in the form of volcanic glass resulted from cooled lava. This paper presents the utilization of M-Sand with partial replacement of unexpanded perlite as a fine aggregate. In the present research, the effect of unexpanded Perlite with M- sand in concrete is studied to determine the mechanical properties such as compressive strength at 7 days, 14 days and 28 days, split tensile strength at 28days and flexural strength at 28 days. M-Sand is used in the range of 62%, 60%, 58%, 56%, 54%, 52% and 50% with Unexpanded Perlite UP in the percentage of 38%, 40%, 42%, 44%, 46%, 48% and 50% respectively. The Unexpanded Perlite can withstand the 1.5 times of thermal resistivity when compared to the conventional concrete

NIMS: a database on nucleobase compounds and their interactions in macromolecular structures

The intense exploration of nucleotide-binding protein structures has created a whirlwind in the field of structural biology and bioinformatics. This has led to the conception and birth of NIMS. This database is a collection of detailed data on the nucleobases, nucleosides and nucleotides, along with their analogues as well as the protein structures to which they bind. Interaction details such as the interacting residues and all associated values have been made available. As a pioneering step, the diffraction precision index for protein structures, the atomic uncertainty for each atom, and the computed errors on the interatomic distances and angles are available in the database. Apart from the above, provision has been made to visualize the three-dimensional structures of both ligands and protein-ligand structures and their interactions in Jmol as well as JSmol. One of the salient features of NIMS is that it has been interfaced with a user-friendly and query-based efficient search engine. It was conceived and developed with the aim of serving a significant section of researchers working in the area of protein and nucleobase complexes. NIMS is freely available online at http://iris.physics.iisc.ernet.in/nims and it is hoped that it will prove to be an invaluable asset

Serial passage of West-European sporadic non-A non-B hepatitis in rhesus monkeys by inoculation with fecal extracts

An experimental model of sporadic non-A non-B hepatitis involving a Fab nonimmune binding activity in stools was established in the rhesus monkey. The first animal was inoculated intravenously with a stool extract from a French patient who had never left the country and in whom post-transfusion hepatitis was excluded. Four passages were performed, and the infection was transmitted by parenteral as well as the oral routes by inoculation of stools or liver extracts. Infection led in three monkeys to reversible hepatocyte injury manifested by a transitory increase in serum aminotransferases. The other three animals, in which persistently high levels of aminotransferases was observed, were sacrificed on day 60 after inoculation. The incubation period, as evidenced by elevation of aminotransferases was about 3 to 4 weeks. The infectious agent was transitorily present in the stools before aminotransferase elevation. The presence of the infectious agent in the stools was correlated with the nonimmune Fab binding activity

Online_DPI: a web server to calculate the diffraction precision index for a protein structure

An online computing server, Online_DPI (where DPI denotes the diffraction precision index), has been created to calculate the `Cruickshank DPI' value for a given three-dimensional protein or macromolecular structure. It also estimates the atomic coordinate error for all the atoms available in the structure. It is an easy-to-use web server that enables users to visualize the computed values dynamically on the client machine. Users can provide the Protein Data Bank (PDB) identification code or upload the three-dimensional atomic coordinates from the client machine. The computed DPI value for the structure and the atomic coordinate errors for all the atoms are included in the revised PDB file. Further, users can graphically view the atomic coordinate error along with `temperature factors' (i.e. atomic displacement parameters). In addition, the computing engine is interfaced with an up-to-date local copy of the Protein Data Bank. New entries are updated every week, and thus users can access all the structures available in the Protein Data Bank. The computing engine is freely accessible online at http://cluster.physics.iisc.ernet.in/dpi/