Abstract:
:Transcription in the human immunodeficiency virus type 1 (HIV-1) retrovirus is regulated by binding the viral Tat protein (trans-acting transcriptional activator) to the trans-activation response (TAR) RNA sequence. Here, vacuum UV circular dichroism (VUV-CD) is used to study the structure of TAR and its complex with two peptide fragments that are important for Tat binding to TAR. The VUV-CD spectrum of TAR is typical of A-form RNA and is minimally perturbed when bound to either the short or the long Tat peptide. The CD spectra of the complexes indicate an extended structure in the arginine-rich region of Tat from amino acid residue 47 through residue 58 and a short alpha-helix within the adjacent 59-72 region. Models of TAR and its peptide complexes are constructed to integrate these spectroscopic results with current biochemical data. The model suggests that (i) the arginine-rich 49-58 region is primarily responsible for electrostatic interactions with the phosphates of the RNA, (ii) the arginine side chains can additionally interact with substituent groups of the nucleotide bases to confer base recognition in the complex, (iii) the recognition of uracil-23 in TAR is facilitated by the peptide backbone, and (iv) the glutamine-rich face of an alpha-helix within the 59-72 region pairs to bases UGG at nucleotide positions 31-33 in the TAR loop and thus provides an additional motif in the Tat trans-activating protein to recognize TAR RNA.
journal_name
Proc Natl Acad Sci U S Aauthors
Loret EP,Georgel P,Johnson WC Jr,Ho PSdoi
10.1073/pnas.89.20.9734keywords:
subject
Has Abstractpub_date
1992-10-15 00:00:00pages
9734-8issue
20eissn
0027-8424issn
1091-6490journal_volume
89pub_type
杂志文章abstract::Transient cytosolic Ca(2+) ([Ca(2+)](cyt)) elevations are early events in plant signaling pathways including those related to abiotic stress. The restoration of [Ca(2+)](cyt) to prestimulus levels involves ATP-driven Ca(2+) pumps, but direct evidence for an essential role of a plant Ca(2+)-ATPase in abiotic stress ada...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0800864105
更新日期:2008-12-09 00:00:00
abstract::The mechanical properties of engineering structures continuously weaken during service life because of material fatigue or degradation. By contrast, living organisms are able to strengthen their mechanical properties by regenerating parts of their structures. For example, plants strengthen their cell structures by tra...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2016524118
更新日期:2021-01-19 00:00:00
abstract::Simian virus 40 (SV40)-transformed hamster cells were relatively resistant to the lytic effect of activated macrophages from animals with chronic intracellular infections. Conversely, SV40-transformed mouse and rat cells and adenovirus 2-transformed hamster cells were highly susceptible to destruction by tumoricidal a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.11.6773
更新日期:1980-11-01 00:00:00
abstract::Human interleukin 12 and interleukin 23 (IL12/23) influence susceptibility or resistance to multiple diseases. However, the reasons underlying individual differences in IL12/23 sensitivity remain poorly understood. Here we report that in human peripheral blood mononuclear cells (PBMCs) and inflamed lungs, the majority...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1515978112
更新日期:2015-12-15 00:00:00
abstract::The VX2 carcinoma-bearing rabbit is an animal model for tumor-induced hypercalcemia, thought to be due to increased bone destruction effected by prostaglandin E2. The present experiments suggest that the pathophysiology of the hypercalcemia differs from that previously proposed. Tumor was transplanted intramuscularly ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.2.640
更新日期:1982-01-01 00:00:00
abstract::We have used DNase I as a probe to examine the chromatin structure of mouse immunoglobulin kappa light chain genes in rearranged and unrearranged chromosomes--i.e., in nuclei from myeloma cells and from brain and liver cells. Tissue-specific DNase I-hypersensitive sites are observed 0.7 and 1.7 kilobases upstream from...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.9.2427
更新日期:1983-05-01 00:00:00
abstract::Despite structural knowledge of broadly neutralizing monoclonal antibodies (NMAbs) complexed to HIV-1 gp120 and gp41 envelope glycoproteins, virus inactivation mechanisms have been difficult to prove, in part because neutralization assays are complex and were previously not understood. Concordant with recent evidence ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1109728109
更新日期:2012-05-15 00:00:00
abstract::The number of large intramembrane particles associated with sites of synaptic vesicle release at the squid giant synapse was determined and compared to the average maximal presynaptic calcium current in order to derive an estimate of the conductance each particle would have if it were a calcium channel. This value, 0....
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.11.7210
更新日期:1981-11-01 00:00:00
abstract::A method has been developed that enables us to identify intracellular degradation intermediates of fructose-bisphosphate aldolase B (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate-lyase, EC 4.1.2.13). This method is based on the use of antibody against thoroughly denatured purified aldolase. This antibody ha...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.18.6114
更新日期:1985-09-01 00:00:00
abstract::Activator 1 (A1; also called replication factor C), in conjunction with proliferating-cell nuclear antigen (PCNA), is essential for the elongation of primed DNA templates by DNA polymerases delta and epsilon. A1 contains five distinct subunits of 145, 40, 38, 37, and 36.5 kDa. Here we describe the isolation, sequence,...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.7.2516
更新日期:1992-04-01 00:00:00
abstract::We identified the phosphatidylinositol transfer protein (PITP) as being responsible for a powerful latent, nucleotide-independent, Golgi-vesiculating activity that is present in the cytosol but is only manifested as an uncontrolled activity in a cytosolic protein subfraction, in which it is separated from regulatory c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.19.11181
更新日期:1998-09-15 00:00:00
abstract::Tridecaptin A1 (TriA1) is a nonribosomal lipopeptide with selective antimicrobial activity against Gram-negative bacteria. Here we show that TriA1 exerts its bactericidal effect by binding to the bacterial cell-wall precursor lipid II on the inner membrane, disrupting the proton motive force. Biochemical and biophysic...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1608623113
更新日期:2016-10-11 00:00:00
abstract::Muscular dystrophy is a general term encompassing muscle disorders that cause weakness and wasting, typically leading to premature death. Membrane instability, as a result of a genetic disruption within the dystrophin-glycoprotein complex (DGC), is thought to induce myofiber degeneration, although the downstream mecha...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0906591106
更新日期:2009-11-10 00:00:00
abstract::Most studies of cytoskeletal organelles have concentrated on molecular analyses of abundant and biochemically accessible structures. In many of the classical cases, however, the nature of the system chosen has precluded a concurrent genetic analysis. The mitotic spindle of the yeast Saccharomyces cerevisiae is one exa...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.8.2468
更新日期:1986-04-01 00:00:00
abstract::We analyzed variability in outer surface protein B (OspB) from Borrelia burgdorferi (Bb), the causative agent of Lyme disease, to determine how Bb escapes immune destruction. We have shown that vaccination with OspB from Bb strain B31 protected mice from infection with Bb B31 but not against Bb N40. The present study ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.9.4092
更新日期:1993-05-01 00:00:00
abstract::B7 family proteins provide costimulatory signals that regulate T cell responses. Here we report the third set of B7 family-related T cell inhibitory molecules with the identification of a homolog of the B7 family, B7x. It is expressed in immune cells, nonlymphoid tissues, and some tumor cell lines. B7x inhibits cell-c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1434299100
更新日期:2003-09-02 00:00:00
abstract::Heteroduplex molecules of pneumococcal DNA, prepared by cross-annealing resolved complementary strands, have been used as donors in transformation. A number of pairs of genetic markers are situated exclusively in the trans configuration in these heteroduplexes. Insertion of two markers from trans configuration into op...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.69.2.466
更新日期:1972-02-01 00:00:00
abstract::We have studied the genetic interactions between mutant alleles in 12 genes, designated PER1-PER12, which are essential for peroxisome biogenesis in the yeast Hansenula polymorpha. Recessive mutations in any of these genes determined three different morphological phenotypes: (i) complete absence of peroxisomes (Per-);...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.16.7470
更新日期:1993-08-15 00:00:00
abstract::Homologous recombination is an important biological process that occurs in all organisms and facilitates genome rearrangements and repair of DNA double-strand breaks. Eukaryotic Rad51 proteins (Rad51sp or Rhp51 in fission yeast) are functional and structural homologs of bacterial RecA protein, an evolutionarily conser...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2632890100
更新日期:2003-12-23 00:00:00
abstract::Natural abundance 13C spin-lattice (T1) relaxation time measurements are reported for unilamellar vesicles of 1,2-dipalmitoylphosphatidylcholine (1,2-dipalmitoyl-sn-glycero-3-phosphocholine), in the liquid crystalline phase, at magnetic field strengths of 1.40, 1.87, 2.35, 4.23, 7.05, 8.45, and 11.7 tesla (resonance f...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.14.4325
更新日期:1983-07-01 00:00:00
abstract::Peptide ligand selection by MHC class I molecules, which occurs by iterative optimization, is the centerpiece of immunodominance in antiviral and antitumor immune responses. For its understanding, the molecular mechanisms of peptide binding and dissociation by class I molecules must be elucidated. To this end, we have...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1418690112
更新日期:2015-01-06 00:00:00
abstract::The maytansinoid drug DM1 is 100- to 1000-fold more cytotoxic than anticancer drugs that are currently in clinical use. The immunoconjugate C242-DM1 was prepared by conjugating DM1 to the monoclonal antibody C242, which recognizes a mucin-type glycoprotein expressed to various extents by human colorectal cancers. C242...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.16.8618
更新日期:1996-08-06 00:00:00
abstract::Individuals with developmental dyslexia vary in their ability to improve reading skills, but the brain basis for improvement remains largely unknown. We performed a prospective, longitudinal study over 2.5 y in children with dyslexia (n = 25) or without dyslexia (n = 20) to discover whether initial behavioral or brain...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1008950108
更新日期:2011-01-04 00:00:00
abstract::Cancer is a genetic disease caused by genomic instability. In many cancers, this instability is manifested by chromosomal reconfigurations and karyotypic complexity. These features are particular hallmarks of the epithelial cancers that are some of the malignancies most resistant to long term control by current chemot...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0405578102
更新日期:2005-02-22 00:00:00
abstract::Components in cerebrospinal fluid that are antigenically related to myelin basic protein have been identified by a technique described recently [Barbarese, E., Braun, P. E. & Carson, J. H. (1977) Proc. Natl. Acad. Sci. USA 74, 3360-3364] involving separating the cerebrospinal fluid proteins by sodium dodecyl sulfate/p...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.4.1976
更新日期:1978-04-01 00:00:00
abstract::Biological membranes are highly dynamic and complex lipid bilayers, responsible for the fate of living cells. To achieve this function, the hydrating environment is crucial. However, membrane imaging typically neglects water, focusing on the insertion of probes, resonant responses of lipids, or the hydrophobic core. O...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1719347115
更新日期:2018-04-17 00:00:00
abstract::Accurate replication in the presence of DNA damage is essential to genome stability and viability in all cells. In Escherichia coli, DNA replication forks blocked by UV-induced damage undergo a partial resection and RecF-catalyzed regression before synthesis resumes. These processing events generate distinct structura...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1300624110
更新日期:2013-07-09 00:00:00
abstract::Signal transduction by two-component systems involves phosphorylation and thereby activation of the response regulator by the cognate histidine kinase. Bifunctional histidine kinases have two opposing activities: depending on the environmental stimuli they either promote phosphorylation or stimulate the rapid dephosph...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.2.604
更新日期:1999-01-19 00:00:00
abstract::We have developed Differential Specificity and Energy Landscape (DiSEL) analysis to comprehensively compare DNA-protein interactomes (DPIs) obtained by high-throughput experimental platforms and cutting edge computational methods. While high-affinity DNA binding sites are identified by most methods, DiSEL uncovered nu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1811431115
更新日期:2018-11-06 00:00:00
abstract::The thymus lacks self-renewing hematopoietic cells, and thymopoiesis fails rapidly when the migration of progenitor cells to the thymus ceases. Hence, the process of thymus homing is an essential step for T-cell development and cellular immunity. Despite decades of research, the molecular details of thymus homing have...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1016428108
更新日期:2011-05-03 00:00:00