Search results for "Structural Biology."
showing 10 items of 822 documents
Multiple roles for ISWI in transcription, chromosome organization and DNA replication.
2003
ISWI functions as the ATPase subunit of multiple chromatin-remodeling complexes. These complexes use the energy of ATP hydrolysis to slide nucleosomes and increase chromatin fluidity, thereby modulating the access of transcription factors and other regulatory proteins to DNA. Here we discuss recent progress toward understanding the biological functions of ISWI, with an emphasis on its roles in transcription, chromosome organization and DNA replication.
The effects of glucocorticoids on thymidine kinase and nucleoside phosphotransferase during development of chicken embryo retina.
1983
AbstractThymidine kinase in chick embryo retina reaches its highest values on the 8–10th day of development, then declines reaching the lowest value at hatching. The rate of DNA synthesis essentially follows this activity while, in contrast, nucleoside phosphotransferase increases progressively during development. Glucocorticoids at 5 × 10−6M lower the level of thymidine kinase in isolated retinas of chick embryo. The most effective steroid was hydrocortisone. The effect was observed in retinas from 8–18-day-old chick embryo and, except on the 18th day, was always of the same magnitude. We suggest that a glucocorticoid can be the natural factor responsible for the marked fall in thymidine k…
Manganese/polymetallic nodules: Micro-structural characterization of exolithobiontic- and endolithobiontic microbial biofilms by scanning electron mi…
2009
Polymetallic/ferromanganese nodules (Mn-nodules) provide a rich source for manganese. It is not yet known if the nodules have a biogenic or an abiogenic origin. Here we applied the technique of high-resolution scanning electron microscopy, in combination with energy dispersive X-ray spectroscopical (EDX) analysis, to trace the existence of microbial biofilms. Two spatially separated assemblies exist, the exolithobiontic- and endolithobiontic colonizations. The exolithobiontic colonization is seen in the micro-canals, which traverse the outer surface layer of the nodules and are formed by elongated filamentous organisms, which show no signs of mineralization. In the center of the nodules thr…
Characterization and transcriptional analysis of Pseudomonas fluorescens denitrifying clusters containing the nar, nir, nor and nos genes
2001
In this study, we report the cloning and characterization of denitrifying gene clusters of Pseudomonas fluorescens C7R12 containing the narXLDKGHJI, nirPOQSM, norCB and nosRZDFYL genes. While consensus sequences for Fnr-like protein binding sites were identified in the promoter regions of the nar, nir, nor and nos genes, consensus sequences corresponding to the NarL binding sites were identified only upstream the nar genes. Monitoring by mRNA analysis the expression of the narG, nirS, norB and nosZ structural genes suggests a sequential induction of the denitrification system in P. fluorescens.
Cloning and tissue expression of two cDNAs encoding the peroxisomal 2-enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase in the guinea pig liver
1996
Abstract The 2-enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase (HD) is the second enzyme of the peroxisomal β-oxidation pathway. In human and rat, only one HD mRNA has been so far detected in the liver. This paper reports for the first time in a mammal species, the guinea pig, the cloning and sequencing of two cDNAs encoding an HD. The 3,274 nucleotide-cDNA is a strictly identical but longer copy of the 2,494 nucleotide-form. A 2,178 by-open reading frame encodes a protein of 726 amino acids ( M r 79.3 kDa) with the peroxisomal-targeting signal (tripeptide SKL) at the carboxyterminus. Northern blot analysis of HD mRNA identified three mRNAs of respective sizes 3.5, 2.6 and 1.6 kb in the…
Cloning and sequencing of the cDNA encoding human glutaredoxin.
1994
Glutaredoxin (thioltransferase) is a small, heat-stable protein, which is involved in thiol/disulfide exchange reactions. We have isolated a cDNA that encodes glutaredoxin from a human brain cDNA library. The encoded protein contains 106 amino acids with a calculated molecular mass of 11.76 kDa and an isoelectric point of 8.09. The amino acid sequence deduced from the cDNA is more than 80% identical to those of other mammalian glutaredoxins.
Rat adrenoleukodystrophy-related (ALDR) gene: full-length cDNA sequence and new insight in expression.
2001
X-linked adrenoleukodystrophy (X-ALD) is an inherited demyelinating disorder due to mutations in the ALD gene, which encodes a peroxisomal ABC half-transporter (ALDP). It has been suggested that ALDP assembles with ALDRP (adrenoleukodystrophy-related protein), a close homologous half-transporter, to form a functional heterodimer. For the first time full-length ALDRP cDNA (5.5 kb) was cloned, and 5' and 3' RACE analysis revealed that alternative usage of polyadenylation sites generates the two transcripts of 3.0 and 5.5 kb observed in the rat in Northern blot analysis. Southern blotting and chromosomal mapping demonstrated one ALDR locus in the rat genome. Characterisation of the 3' flanking…
Identification of a novel Drosophila melanogaster gene, angel, a member of a nested gene cluster at locus 59F4,5.
1996
The identification of a novel Drosophila melanogaster gene, angel, is presented in this study. angel is located on the right arm of the second chromosome at locus 59F5, close to the nested genes l(2)tid, l(2)not, l(2)rot and l(2)dtl. We describe the genetic and molecular localization of angel and present its temporal expression in the wild-type. The deduced amino acid sequence of the ANG39 protein is characterized by a nuclear localization signal. Furthermore, the central part of the predicted ANG39 protein shows significant homology to the C-terminal portion of the yeast transcriptional effector CCR4.
Immunoglobulin-like domain is present in the extracellular part of the receptor tyrosine kinase from the marine sponge Geodia cydonium.
1994
We have isolated and characterized two cDNAs from the marine sponge Geodia cydonium coding for a new member of a receptor tyrosine kinase of class II. The deduced amino acid sequence shows two characteristic domains: (i) the tyrosine kinase domain; and (ii) and immunoglobulin-like domain. The latter part shows high homology to the vertebrate C2 type immunoglobulin domain. This result demonstrates that immunoglobulin domains are not recent achievements of higher animals but exist also in those animals which have diverged from other organisms about 800 million years ago.
Structure of SNX9 SH3 in complex with a viral ligand reveals the molecular basis of its unique specificity for alanine-containing class I SH3 motifs
2021
Class I SH3 domain-binding motifs generally comply with the consensus sequence [R/K]x0PxxP, the hydrophobic residue 0 being proline or leucine. We have studied the unusual 0 = Ala-specificity of SNX9 SH3 by determining its complex structure with a peptide present in eastern equine encephalitis virus (EEEV) nsP3. The structure revealed the length and composition of the n-Src loop as important factors determining specificity. We also compared the affinities of EEEV nsP3 peptide, its mutants, and cellular ligands to SNX9 SH3. These data suggest that nsP3 has evolved to minimize reduction of conformational entropy upon binding, hence acquiring stronger affinity, enabling takeover of SNX9. The R…