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Yasmina Mirassou Montserrat Elías-Arnanz S. Padmanabhan M. Angeles Jiménez 《Biomolecular NMR assignments》2013,7(1):51-55
CdnL, an essential protein in Myxococcus xanthus and several other bacteria, is a member of the large CarD_TRCF family of bacterial proteins that interact with RNA polymerase. Structural analyses of the 164-residue M. xanthus CdnL by NMR is complicated because of broadening, and hence overlap, of the signals due to the self-association and the monomer–dimer equilibrium that occurs in solution. Here, we report 1H, 13C and 15N assignments for CdnL achieved by analyzing its NMR spectra on the basis of the complete assignment obtained in this study for the 68-residue N-terminal fragment of CdnL (CdnLNt) together with those we described previously for the stable, protease-resistant, 110-residue C-terminal domain (CdnLCt). This approach relied on our observation that many of the CdnLNt and CdnLCt chemical shifts matched closely with those of the equivalent residues in the full-length protein. Our assignments provide the crucial first step in the structural analysis of CdnL and this functionally important family of bacterial proteins. 相似文献
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Plants of the genus Dieffenbachia, very popular as indoor ornamental plants, are known for their toxic as well as therapeutic properties. Their toxic manifestations have been partly attributed to their proteolytic activity. The work described in the present paper shows that stem leaves and petiole of Dieffenbachia maculata Schott, a commonly grown species, contain significant proteolytic activity, different parts showing different types of protease activities. Stem showed the highest enzyme activity and this protease was purified about 55 fold by solvent precipitation, gel filtration and ion exchange chromatography. The enzyme has a relative molecular mass of 61 kDa as determined by SDS-PAGE and has an optimum pH of 8.0 and optimum temperature of 50 degrees C. Effects of various substrates, inhibitors and activators indicate that the enzyme is a cysteine protease with leucylpeptidase activity. 相似文献
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Basuroy Krishnayan Kantharaju Kamanna Aravinda Subrayashastry Shamala Narayanaswamy Balaram Padmanabhan 《Amino acids》2019,51(9):1297-1306
Amino Acids - Gamma-aminobutyric acid (GABA, gammaAbu), an unsubstituted gamma-amino acid, is an important inhibitory neurotransmitter in the mammalian brain. The role of GABA in the treatment of... 相似文献
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Valerie J. Klema Mengyi Ye Aditya Hindupur Tadahisa Teramoto Keerthi Gottipati Radhakrishnan Padmanabhan Kyung H. Choi 《PLoS pathogens》2016,12(2)
Flavivirus nonstructural protein 5 (NS5) consists of methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, which catalyze 5’-RNA capping/methylation and RNA synthesis, respectively, during viral genome replication. Although the crystal structure of flavivirus NS5 is known, no data about the quaternary organization of the functional enzyme are available. We report the crystal structure of dengue virus full-length NS5, where eight molecules of NS5 are arranged as four independent dimers in the crystallographic asymmetric unit. The relative orientation of each monomer within the dimer, as well as the orientations of the MTase and RdRp domains within each monomer, is conserved, suggesting that these structural arrangements represent the biologically relevant conformation and assembly of this multi-functional enzyme. Essential interactions between MTase and RdRp domains are maintained in the NS5 dimer via inter-molecular interactions, providing evidence that flavivirus NS5 can adopt multiple conformations while preserving necessary interactions between the MTase and RdRp domains. Furthermore, many NS5 residues that reduce viral replication are located at either the inter-domain interface within a monomer or at the inter-molecular interface within the dimer. Hence the X-ray structure of NS5 presented here suggests that MTase and RdRp activities could be coordinated as a dimer during viral genome replication. 相似文献
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Summary 1. In the teleostTilapia mossambica (Peters), new crops of oocytes arise from nests of cells of the germinal epithelium as well as from the epithelial strands ramifying into the ovocoel.2. There is no evidence to indicate that degenerating follicle cells form a source for a new crop of oocytes.3. After one spawning is over, the follicular layer of the mature unspawned ova alone undergo atresia.4. Neither immature oocytes nor oocytes in the growth stages undergo degeneration.5. The occurrence of immature, maturing, and fully ripe ova in the ovary at a particular time account for asynchronism inTilapia mossambica.
Origine des poussées ovocytaires chezTilapia mossambica
Extrait L'ovaire deTilapia mossambica a été étudié dans le but de préciser l'origine des poussées ovocytaires. Après la ponte l'ovaire n'est pas vide pour autant, et il y subsiste des ovocytes à tous les stades du développement. Les replis de l'épithélium germinatif et les tractus épithéliaux ramifiés contiennent des flots de cellules qui produisent des ovogonies primaires, lesquelles se transforment en ovocytes et en cellules folliculaires. Il ne semble pas qu'une nouvelle poussée ovocytaire puisse se faire à partir des résidus des follicules des ovocytes atrétiques. Seuls les ovules mûrs non évacués par la ponte subissent une atrésie et se résorbent; les ovocytes immatures ou en voie de croissance ne dégénèrent pas. L'asynchronisme deT. mossambica se traduit par la présence simultanée, dans l'ovaire, d'ovocytes à tous les stades de croissance et de maturation.相似文献
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