Search results for "Sequence"
showing 10 items of 4987 documents
Recurrent domestication by Lepidoptera of genes from their parasites mediated by Bracoviruses
2015
Bracoviruses are symbiotic viruses associated with tens of thousands of species of parasitic wasps that develop within the body of lepidopteran hosts and that collectively parasitize caterpillars of virtually every lepidopteran species. Viral particles are produced in the wasp ovaries and injected into host larvae with the wasp eggs. Once in the host body, the viral DNA circles enclosed in the particles integrate into lepidopteran host cell DNA. Here we show that bracovirus DNA sequences have been inserted repeatedly into lepidopteran genomes, indicating this viral DNA can also enter germline cells. The original mode of Horizontal Gene Transfer (HGT) unveiled here is based on the integrativ…
Secuencias ponderadoras de identificación con como en textos literarios y periodísticos cubanos (2000-2008)
2013
La presente investigación analiza, a partir de textos cubanos actuales, un tipo de construcciones que proponemos denominar «secuencias ponderadoras de identificación con como». Se explica su funcionamiento en calidad de construcción lingüística peculiar mediante la descripción e interpretación de sus características morfosintácticas y semánticas. By examining current Cuban texts, this study analyzes a type of constructions which are proposed to be denominated 'emphatic sequences of identification with como'. It tries to explain these sequences as a peculiar linguistic construction by means of the description and interpretation of their morphosyntactic and semantic characteristics.
Analysis of Multilocus Sequence Typing and Virulence Characterization of Listeria monocytogenes Isolates from Chinese Retail Ready-to-Eat Food
2016
Eighty Listeria monocytogenes isolates were obtained from Chinese retail ready-to-eat (RTE) food and were previously characterized with serotyping and antibiotic susceptibility tests. The aim of this study was to characterize the subtype and virulence potential of these L. monocytogenes isolates by multilocus sequence typing (MLST), virulence-associate genes, epidemic clones (ECs), and sequence analysis of the important virulence factor: internalin A (inlA). The result of MLST revealed that these L. monocytogenes isolates belonged to 14 different sequence types (STs). With the exception of four new STs (ST804, ST805, ST806, and ST807), all other STs observed in this study have been associat…
Uncapping the N-terminus of a ubiquitous His-tag peptide enhances its Cu2+ binding affinity
2019
Metal complexes with an N-terminally free and N-terminally acetylated polyhistidine region of Echis ocellatus venom, with an interesting His-rich motif present in numerous metal binding proteins from all kingdoms of life (DHDHDHHHHHHPGSSV-NH2 and Ac-DHDHDHHHHHHPGSSV-NH2) show the role of the free amino group in the thermodynamic enhancement of Cu2+, Ni2+ and Zn2+ binding. In the studied sequences, Cu2+ can be coordinated by different sets of imidazole rings, and a 3–10 helix is detected in close proximity of Cu2+ binding sites. The complexes are more stable than those with a typical His6-tag, despite a similar copper(II) coordination mode in both cases.
The effect of nanoparticle size and NLS density on nuclear targeting in cancer and normal cells; impaired nuclear import and aberrant nanoparticle in…
2017
The cell nucleus is an interesting target in many diseases with particular interest in cancer. Previously, nuclear targeted small and large chitosan nanoparticles (S-NPs≈25nm, and L-NPs≈150nm respectively), modified with low, intermediate and high densities of NLS (L-NLS, I-NLS and H-NLS) were developed and assessed in L929 fibroblasts. However, to evade apoptosis and stimulate tumor growth cancer cells are capable of manipulating the nuclear-cytoplasmic transport on many levels, making NPs that are capable of nuclear targeting in normal cells incapable of doing so in cancer. For such reason, here, the nuclear delivery efficiency of S-NPs and L-NPs was assessed as a function of their NLS de…
Redox modulation of Rubisco conformation and activity through its cysteine residues
2008
Treatment of purified Rubisco with agents that specifically oxidize cysteine-thiol groups causes catalytic inactivation and increased proteolytic sensitivity of the enzyme. It has been suggested that these redox properties may sustain a mechanism of regulating Rubisco activity and turnover during senescence or stress. Current research efforts are addressing the structural basis of the redox modulation of Rubisco and the identification of critical cysteines. Redox shifts result in Rubisco conformational changes as revealed by the alteration of its proteolytic fragmentation pattern upon oxidation. In particular, the augmented susceptibility of Rubisco to proteases is due to increased exposure…
Phosphorylation of the Goodpasture antigen by type A protein kinases.
1995
Collagen IV is the major component of basement membranes. The human alpha 3 chain of collagen IV contains an antigenic domain called the Goodpasture antigen that is the target for the circulating immunopathogenic antibodies present in patients with Goodpasture syndrome. Characteristically, the gene region encoding the Goodpasture antigen generates multiple alternative products that retain the antigen amino-terminal region with a five-residue motif (KRGDS). The serine therein appears to be the major in vitro cAMP-dependent protein kinase phosphorylation site in the isolated antigen and can be phosphorylated in vitro by two protein kinases of approximately 50 and 41 kDa associated with human …
Iron Induces Proliferation and Morphogenesis in Primmorphs from the Marine SpongeSuberites domuncula
2002
Dissociated cells from marine demosponges retain their proliferation capacity if they are allowed to form special aggregates, the primmorphs. On the basis of incorporation studies and septin gene expression, we show that Fe3+ ions are required for the proliferation of cells in primmorphs from Suberites domuncula. In parallel, Fe3+ induced the expression of ferritin and strongly stimulated the synthesis of spicules. This result is supported by the finding that the enzymatic activity of silicatein, converting organosilicon to silicic acid, depends on Fe3+. Moreover, the expression of a scavenger receptor molecule, possibly involved in the morphology of spicules, depends on the presence of Fe3…
The fnr Gene of Bacillus licheniformis and the Cysteine Ligands of the C-Terminal FeS Cluster
1998
Many of the O2-responsive gene regulators of bacteria are members of the fumarate nitrate reductase-cyclic AMP receptor protein family of transcriptional regulators (12, 13, 15, 17) with predicted structures similar to those of the cyclic AMP receptor protein (11). The Fnr (stands for fumarate nitrate reductase regulator) protein from Escherichia coli (FnrEc) controls the expression of a variety of genes, mainly of anaerobic respiration and metabolism (5, 13). It contains a N-terminal cluster of three essential cysteine residues which are supposed to bind together with Cys122 a [4Fe 4S]2+ cluster which is required for O2 sensing (4, 7, 8, 10, 16). A wide variety of gram-negative bacteria co…
Truncated recombinant light harvesting complex II proteins are substrates for a protein kinase associated with photosystem II core complexes
1998
AbstractPrevious studies directed towards understanding phosphorylation of the chlorophyll a/b binding proteins comprising light harvesting complex II (LHC II) have concentrated on a single phosphorylation site located close to the N-terminus of the mature proteins. Here we show that a series of recombinant pea Lhcb1 proteins, each missing an N-terminal segment including this site, are nevertheless phosphorylated by a protein kinase associated with a photosystem II core complex preparation. An Lhcb1 protein missing the first 58 amino acid residues is not, however, phosphorylated. The results demonstrate that the LHC II proteins are phosphorylated at one or more sites, the implications of wh…