Abstract:
:Recently, we established that satellite III (TGGAA)n tandem repeats, which occur at the centromeres of human chromosomes, pair with themselves to form an unusual "self-complementary" antiparallel duplex containing (GGA)2 motifs in which two unpaired guanines from opposite strands intercalate between sheared G.A base pairs. In separate studies, we have also established that the GCA triplet does not form bimolecular (GCA)2 motifs but instead promotes the formation of hairpins containing a GCA-turn motif in which the loop contains a single cytidine closed by a sheared G.A pair. Since TGCAA is the most frequent variant of TGGAA found in satellite III repeats, we reasoned that the potential of this variant to form GCA-turn miniloop fold-back structures might be an important factor in modulating the local structure in natural (TGGAA)n repeats. We report here the NMR-derived solution structure of the heptadecadeoxynucleotide (G)TGGAATGCAATGGAA(C) in which a central TGCAA pentamer is flanked by two TGGAA pentamers. This 17-mer forms a rather unusual and very stable hairpin structure containing eight base pairs in the stem, only four of which are Watson-Crick pairs, and a loop consisting of a single cytidine residue. The stem contains a (GGA)2 motif with intercalative 14G/4G stacking between two sheared G.A base pairs; the loop end of the stem consists of a sheared 8G.10A closing pair with the cytosine base of the 9C loop stacked on 8G. The remarkable stability of this unusual hairpin structure (Tm = 63 degrees C) suggests that it probably plays an important role in modulating the folding of satellite III (TGGAA)n repeats at the centromere.
journal_name
Proc Natl Acad Sci U S Aauthors
Zhu L,Chou SH,Reid BRdoi
10.1073/pnas.93.22.12159subject
Has Abstractpub_date
1996-10-29 00:00:00pages
12159-64issue
22eissn
0027-8424issn
1091-6490journal_volume
93pub_type
杂志文章abstract::Myosin generates force by a rotation of its lever arm. Crystal structures of myosin II indicate an unloaded working stroke of 10-12 nm, a range confirmed by recent x-ray interference experiments. However, when an actin filament, held between two weakly, optically trapped beads is made to interact with a single head of...
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.0506272103
更新日期:2006-01-31 00:00:00
abstract::We estimated the unliganded opening and closing rate constants of neuromuscular acetylcholine receptor-channels (AChRs) having mutations that increased the gating equilibrium constant. For some mutant combinations, spontaneous openings occurred in clusters. For 25 different constructs, the unliganded gating equilibriu...
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.0809272106
更新日期:2009-01-06 00:00:00
abstract::The epidermal growth factor receptor gene has been found to be amplified and rearranged in human glioblastomas in vivo. Here we present the sequence across a splice junction of aberrant epidermal growth factor receptor transcripts derived from corresponding and uniquely rearranged genes that are coamplified and coexpr...
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.87.21.8602
更新日期:1990-11-01 00:00:00
abstract::Scattering of light from dielectric particles whose size is on the order of an optical wavelength underlies a plethora of visual phenomena in nature and is a foundation for optical coatings and paints. Tailoring the internal nanoscale geometry of such "photonic particles" allows tuning their optical scattering charact...
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.1601777113
更新日期:2016-06-21 00:00:00
abstract::A reversible growth arrest of simian virus 40-transformed human fibroblasts has been produced by replacement of methionine in the growth medium by its immediate metabolic precursor, homocysteine, Although these arrested cells exhibit a greatly reduced cloning efficiency when plated in methionine-supplemented medium, t...
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.77.12.7306
更新日期:1980-12-01 00:00:00
abstract::Protein aggregation is a hallmark of many diseases, including amyotrophic lateral sclerosis (ALS), where aggregation of Cu/Zn superoxide dismutase (SOD1) is implicated in causing neurodegeneration. Recent studies have suggested that destabilization and aggregation of the most immature form of SOD1, the disulfide-reduc...
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.0913021108
更新日期:2011-02-08 00:00:00
abstract::Myofibril formation was visualized in cultured live cardiomyocytes that were transfected with plasmids expressing green fluorescent protein (GFP) linked to the Z-band protein, alpha-actinin. The expression of this fluorescent protein provided an in vivo label for structures containing alpha-actinin. The GFP-alpha-acti...
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.94.17.9493
更新日期:1997-08-19 00:00:00
abstract::The effects of three anti-inflammatory drugs, which interfere with arachidonic acid transformation by three different enzymes, have been compared by using a simple model of tissue damage and foreign body rejection. In groups of control rats, subcutaneously implanted polyester sponges were rejected after a mean of 12 d...
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.81.9.2890
更新日期:1984-05-01 00:00:00
abstract::We have isolated a lymphoid cell line, MDS, from the pleural exudate of a patient with chronic myelomonocytic leukemia. The cells are biphenotypic, containing various T-cell and myeloid markers, and are surface negative for CD4 and CD8 but have low CD4 mRNA. The cells grow in suspension with a doubling time of 15 hr, ...
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.89.21.9996
更新日期:1992-11-01 00:00:00
abstract::Novel cellular behaviors and characteristics can be obtained by coupling engineered gene networks to the cell's natural regulatory circuitry through appropriately designed input and output interfaces. Here, we demonstrate how an engineered genetic circuit can be used to construct cells that respond to biological signa...
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.0402940101
更新日期:2004-06-01 00:00:00
abstract::A major goal for developmental biologists is to define the behaviors and molecular contents of differentiating cells. We have devised a strategy for isolating cells from diverse embryonic regions and stages in the zebrafish, using computer-guided laser photoconversion of injected Kaede protein and flow cytometry. This...
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.0805589105
更新日期:2008-08-26 00:00:00
abstract::Activation-induced cytidine deaminase (AID) is essential to class-switch recombination (CSR) and somatic hypermutation (SHM) in both V region SHM and S region SHM (s-SHM). Uracil DNA glycosylase (UNG), a member of the base excision repair (BER) complex, is required for CSR. Strikingly, however, UNG deficiency causes 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.1402391111
更新日期:2014-03-18 00:00:00
abstract::Telomerase is an RNA-directed DNA polymerase, composed of RNA and protein subunits, that replicates the telomere ends of linear eukaryotic chromosomes. Using a genetic strategy described here, we identify the product of the EST2 gene, Est2p, as a subunit of telomerase in the yeast Saccharomyces cerevisiae. Est2p is re...
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.94.17.9202
更新日期:1997-08-19 00:00:00
abstract::The functional role of residue Tyr-19 of Chromatium vinosum HiPIP has been evaluated by site-directed mutagenesis experiments. The stability of the [Fe4S4] cluster prosthetic center is sensitive to side-chain replacements. Polar residues result in significant instability, while nonpolar residues (especially with aroma...
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.92.21.9440
更新日期:1995-10-10 00:00:00
abstract::The importance of core histones in the regulation of DNA function by chromatin is clear. However, little is known about the role of the linker histone. We investigated the role of H1 in Saccharomyces cerevisiae during extensive transcriptional reprogramming in stationary phase. Although the levels of linker histone Hh...
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.0806337105
更新日期:2008-09-30 00:00:00
abstract::Subunits A and B of chloroplast glyceraldehyde-3-phosphate dehydrogenase are synthesized as higher molecular weight precursors when polyadenylylated mRNA from angiosperm seedlings is translated in vitro by wheat germ ribosomes. The in vivo levels of mRNA coding for these precursors are strongly light dependent, and th...
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.79.24.7624
更新日期:1982-12-01 00:00:00
abstract::The rat insulin-like growth factor II gene, encoding a fetal somatomedin, expresses a multitranscript family in embryonic/fetal tissues and in the adult brain and spinal cord. By performing in situ hybridization on tissue sections of adult brain and spinal cord, we have found that these transcripts are not expressed i...
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.85.1.141
更新日期:1988-01-01 00:00:00
abstract::When the visual (striate) cortex (V1) is damaged in human subjects, cortical blindness results in the contralateral visual half field. Nevertheless, under some experimental conditions, subjects demonstrate a capacity to make visual discriminations in the blind hemifield (blindsight), even though they have no phenomena...
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.92.13.6122
更新日期:1995-06-20 00:00:00
abstract::Activated thiol-Sepharose [agarose-(glutathione-2-pyridyl disulfide) conjugate] has been used to immobilize proteins with a single or a few thiol groups via disulfide bridges. The immobilized proteins were subsequently proteolytically degraded. After washing, the thiol-containing peptides were eluted with a reducing 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.72.8.3029
更新日期:1975-08-01 00:00:00
abstract::A 1H NMR study of the 79-residue globular domain of chicken erythrocyte histone H5 (GH5) is presented. Using a combination of two-dimensional NMR techniques to demonstrate through-bond and through-space (less than 5 A) connectivities, the resonances of GH5 are assigned in a sequential manner. From a qualitative interp...
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.83.20.7628
更新日期:1986-10-01 00:00:00
abstract::We describe a Xenopus mRNA, Xrel1, that is related to the avian protooncogene c-rel, the embryonic pattern gene dorsal of Drosophila, and the mammalian transcription factor NK-kappa B/KBF1. The sequence of Xrel1 is homologous to the other rel-related proteins in the large amino-terminal region that defines this class ...
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.88.7.2697
更新日期:1991-04-01 00:00:00
abstract::We have examined the 270 MHz nuclear magnetic resonance spectrum and relaxation kinetic behavior of tRNA2Glu (E. coli) in the absence of Mg++, a condition which produces an inactive form of this tRNA. The results show that the denatured form has about five fewer proton resonances in the region from -12 to -15 ppm. Rel...
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.73.7.2216
更新日期:1976-07-01 00:00:00
abstract::Remarkable progress has come from whole-brain models linking anatomy and function. Paradoxically, it is not clear how a neuronal dynamical system running in the fixed human anatomical connectome can give rise to the rich changes in the functional repertoire associated with human brain function, which is impossible to ...
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.1921475117
更新日期:2020-04-28 00:00:00
abstract::In the search for selective and long-acting analogs of somatostatin, nearly 200 compounds were synthesized by solid-phase methods, purified, and tested biologically. Among these octapeptides, some contained N-terminal (Formula: see text) were 177 times and 113 times more potent, respectively, than somatostatin in test...
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.83.6.1896
更新日期:1986-03-01 00:00:00
abstract::The protease encoded by the human immunodeficiency virus (HIV) processes the viral gag and gag-pol protein precursor by posttranslational cleavage. In this study we have demonstrated by site-specific mutagenesis (Asp----Thr) and by pepstatin A inhibition that the recombinant HIV protease is an aspartic-type protease. ...
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.85.18.6612
更新日期:1988-09-01 00:00:00
abstract::In this paper, Vafa's approach to the formulation of conformal field theories is combined with the formal calculus developed in Frenkel, Lepowsky, and Meurman's work on the vertex operator construction of the Monster to give a geometric definition of vertex operator algebras. The main result announced is the equivalen...
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.88.22.9964
更新日期:1991-11-15 00:00:00
abstract::Jasmonates (JAs) are plant-specific signaling molecules that steer a diverse set of physiological and developmental processes. Pathogen attack and wounding inflicted by herbivores induce the biosynthesis of these hormones, triggering defense responses both locally and systemically. We report on alterations in the tran...
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.0711203105
更新日期:2008-01-29 00:00:00
abstract::Resistance to the antibiotic fusidic acid (FA) in the human pathogen Staphylococcus aureus usually results from expression of FusB-type proteins (FusB or FusC). These proteins bind to elongation factor G (EF-G), the target of FA, and rescue translation from FA-mediated inhibition by an unknown mechanism. Here we show ...
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.1117275109
更新日期:2012-02-07 00:00:00
abstract::A cyclic hexapeptide, cyclo(Pro-Gly-Pro-Gly-Pro-Gly), has been synthesized; its solution conformations were examined by 220-MHz nuclear magnetic resonance spectroscopy. The solution structures have been deduced, and shown to vary as a function of solvent polarity. In addition, it has been found that this cyclic peptid...
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.69.7.1825
更新日期:1972-07-01 00:00:00
abstract::A simple method combining photolithography and shadow (or angle) evaporation is developed to fabricate single-walled carbon nanotube (SWCNT) devices with tube lengths of approximately 10-50 nm between metal contacts. Large numbers of such short devices are obtained without the need of complex tools such as electron be...
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.0404450101
更新日期:2004-09-14 00:00:00