Abstract:
:Two operators, spatially separated from each other and from the promoters, repress the gal operon when bound to Gal repressor. Conversion of either gal operator to a lac operator results in derepression, although both Gal and Lac repressors are present, suggesting that mere occupation of operator sites is not sufficient to cause repression. Conversion of both operators to lac operators restores normal repression in the presence of Lac repressor protein. We propose that normal repression requires interaction between operator-bound like repressor molecules; this generates a DNA loop, which is part of a higher order structure. RNA polymerase and cyclic AMP receptor protein are present in this complex but unable to initiate transcription because of the higher order structure. Such higher order DNA-multiprotein complexes could occur in a variety of genetic regulatory systems that are controlled from distal sites by regulatory proteins.
journal_name
Proc Natl Acad Sci U S Aauthors
Haber R,Adhya Sdoi
10.1073/pnas.85.24.9683subject
Has Abstractpub_date
1988-12-01 00:00:00pages
9683-7issue
24eissn
0027-8424issn
1091-6490journal_volume
85pub_type
杂志文章abstract::We described previously a mutation in maize, hcf106, caused by the insertion of a Mu1 transposon. When the Mu transposon system is in an active phase, hcf106 conditions a nonphotosynthetic, pale green phenotype. However, when the Mu system is inactive (a state correlated with hypermethylation of Mu elements), the plan...
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.88.8.3502
更新日期:1991-04-15 00:00:00
abstract::Steroidogenic factor-1 (SF-1) and liver receptor homologue-1 (LRH-1) belong to the fushi tarazu factor 1 subfamily of nuclear receptors. SF-1 is an essential factor for sex determination during development and regulates adrenal and gonadal steroidogenesis in the adult, whereas LRH-1 is a critical factor for developmen...
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.0409482102
更新日期:2005-05-24 00:00:00
abstract::Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators ...
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.1517092112
更新日期:2016-01-05 00:00:00
abstract::In 1944, Freeman Dyson conjectured the existence of a "crank" function for partitions that would provide a combinatorial proof of Ramanujan's congruence modulo 11. Forty years later, Andrews and Garvan successfully found such a function and proved the celebrated result that the crank simultaneously "explains" the thre...
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.0506702102
更新日期:2005-10-25 00:00:00
abstract::Reversible biological electron transfer usually occurs between redox couples at standard redox potentials ranging from +0.8 to -0.5 V. Dearomatizing benzoyl-CoA reductases (BCRs), key enzymes of the globally relevant microbial degradation of aromatic compounds at anoxic sites, catalyze a biological Birch reduction bey...
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.1819636116
更新日期:2019-02-05 00:00:00
abstract::An src/yes-related novel gene named syn (SYN in human gene nomenclature) has been identified in the human genome on chromosome 6 and characterized by molecular cloning. Nucleotide sequence analysis of cDNA clones showed that the c-syn gene could encode a protein-tyrosine kinase that is very similar in primary structur...
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.83.15.5459
更新日期:1986-08-01 00:00:00
abstract::We obtain a collection of multilinear Littlewood-Paley estimates, which we then apply to two problems in partial differential equations. The first problem is the estimation of the square root of an elliptic operator in divergence form, and the second is the estimation of solutions to the Cauchy problem for nondivergen...
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.79.18.5746
更新日期:1982-09-01 00:00:00
abstract::Most guanine nucleotide binding protein (G protein)-coupled receptors have a conserved cysteine in the C-terminal cytoplasmic tail near the seventh transmembrane spanning region. This cysteine is known to be palmitoylated in rhodopsin, the beta 2-adrenergic receptor (beta 2AR) and the alpha 2A-adrenergic receptor (alp...
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.91.23.11178
更新日期:1994-11-08 00:00:00
abstract::Using an antiserum raised against a synthetic C-terminal peptide of porcine pancreastatin, we detected pancreastatin-like immunoreactivity (PLI) in human pancreatic islets, adrenal medulla, and endocrine tumors. From a carcinoid liver metastasis, human PLI was extracted and purified by HPLC. Two C-terminally amidated ...
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.85.21.8231
更新日期:1988-11-01 00:00:00
abstract::Biomass burning drives changes in greenhouse gases, climate-forcing aerosols, and global atmospheric chemistry. There is controversy about the magnitude and timing of changes in biomass burning emissions on millennial time scales from preindustrial to present and about the relative importance of climate change and hum...
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.1807172115
更新日期:2018-12-04 00:00:00
abstract::The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was recently shown to negatively regulate LPS-induced acute inflammatory responses. We previously observed that the metabolic thiol antioxidant alpha-lipoic acid (LA) inhibits LPS-induced expression of cellular adhesion molecules and adheren...
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.0700305104
更新日期:2007-03-06 00:00:00
abstract::Although an inverse relationship is expected in ancient DNA samples between the number of surviving DNA fragments and their length, ancient DNA sequencing libraries are strikingly deficient in molecules shorter than 40 bp. We find that a loss of short molecules can occur during DNA extraction and present an improved s...
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.1314445110
更新日期:2013-09-24 00:00:00
abstract::Biocompatible gold nanoparticles designed to absorb light at wavelengths of high tissue transparency have been of particular interest for biomedical applications. The ability of such nanoparticles to convert absorbed near-infrared light to heat and induce highly localized hyperthermia has been shown to be highly effec...
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.1906929116
更新日期:2019-09-10 00:00:00
abstract::NifEN is a key player in the biosynthesis of nitrogenase MoFe protein. It not only shares a considerable degree of sequence homology with the MoFe protein, but also contains clusters that are homologous to those found in the MoFe protein. Here we present an investigation of the catalytic activities of NifEN. Our data ...
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.0907872106
更新日期:2009-10-06 00:00:00
abstract::Gene expression is controlled by sequence-specific transcription factors (TFs), which bind to regulatory sequences in DNA. TF binding occurs in nucleosome-depleted regions of DNA (NDRs), which generally encompass regions with lengths similar to those protected by nucleosomes. However, less is known about where within ...
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.1804663115
更新日期:2018-07-24 00:00:00
abstract::Regulation of irreversible cell lineage commitment depends on a delicate balance between positive and negative regulators, which comprise a sophisticated network of transcription factors. Receptor activator of NF-kappaB ligand (RANKL) stimulates the differentiation of bone-resorbing osteoclasts through the induction 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.0912779107
更新日期:2010-02-16 00:00:00
abstract::Invariant natural killer T (iNKT) cells recognize self lipid antigens presented by CD1d molecules. The nature of the self-antigens involved in the development and maturation of iNKT cells is poorly defined. Lysophospholipids are self-antigens presented by CD1d that are generated through the action of phospholipases A1...
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.1302923110
更新日期:2013-03-26 00:00:00
abstract::Bluetongue virus (BTV), a major threat to livestock, is a multilayered, nonturreted member of the Reoviridae, a family of segmented dsRNA viruses characterized by endogenous RNA transcription through an RNA-dependent RNA polymerase (RdRp). To date, the structure of BTV RdRp has been unknown, limiting our mechanistic u...
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.1905849116
更新日期:2019-08-13 00:00:00
abstract::The bidirectional self-assembly of tobacco mosaic virus (TMV, common or U1 strain) has been studied extensively in vitro. Foreign single-stranded RNA molecules containing the TMV origin-of-assembly sequence (OAS, 75-432 nt in length) are also packaged by TMV coat protein (CP) in vitro to form helical pseudovirus parti...
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.91.19.9067
更新日期:1994-09-13 00:00:00
abstract::We report the complete sequence of an extreme halophile, Halobacterium sp. NRC-1, harboring a dynamic 2,571,010-bp genome containing 91 insertion sequences representing 12 families and organized into a large chromosome and 2 related minichromosomes. The Halobacterium NRC-1 genome codes for 2,630 predicted proteins, 36...
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.190337797
更新日期:2000-10-24 00:00:00
abstract::A hallmark of most neurodegenerative diseases, including those caused by polyglutamine expansion, is the formation of ubiquitin (Ub)-positive protein aggregates in affected neurons. This finding suggests that the Ub system may be involved in common mechanisms underlying these otherwise unrelated diseases. Here we repo...
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.1530212100
更新日期:2003-07-22 00:00:00
abstract::We have purified a protein from Necturus maculosus gallbladder cells that forms chloride channels in an artificial membrane. The same protein apparently can form channels that are highly selective for chloride but can have conductances varying from 9 to about 150 pS. The high-conductance channels are blocked by the mo...
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.90.12.5691
更新日期:1993-06-15 00:00:00
abstract::Located within the brain's ventricles, the choroid plexus produces cerebrospinal fluid and forms an important barrier between the central nervous system and the blood. For unknown reasons, the choroid plexus produces high levels of the protein klotho. Here, we show that these levels naturally decline with aging. Deple...
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.1808609115
更新日期:2018-11-27 00:00:00
abstract::The 5' region of the mouse gamma-glutamyltransferase (gamma GT; EC 2.3.2.2) gene has been cloned and analyzed. This analysis, combined with sequence information obtained from gamma GT cDNA clones, indicates that in mouse a single gamma GT gene codes for six different mRNAs that differ in their 5' sequences. Analysis 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.90.13.6179
更新日期:1993-07-01 00:00:00
abstract::Initiation of adenovirus DNA replication in vitro occurs on a linearized plasmid DNA containing 3,327 base pairs of the adenovirus terminal sequence. Various deletions have been constructed in the plasmid DNA and their template activities examined. Deletions from an internal restriction enzyme cleavage site that retai...
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.80.21.6446
更新日期:1983-11-01 00:00:00
abstract::A photolyzable derivative of dipeptidyl-tRNA, p-azido-N-tBoc-Phe-[3H]Phe-tRNA, bound reversibly to 70S ribosomes in the presence of poly(U), becomes, when irradiated, covalently attached to components of the 50S ribosomal subunit. Most of the reaction occurs within the 23S RNA, while ribosomal proteins are only weakly...
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.72.11.4332
更新日期:1975-11-01 00:00:00
abstract::A sensitive in vitro crosslinking technique using a photoactive derivative of the chimeric activator LexA-E2F-1 was used to identify yeast proteins that might influence the response of RNA polymerase II to transcriptional activators. We found that a novel yeast protein, Xtc1p, could be covalently crosslinked to the ac...
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.95.19.11122
更新日期:1998-09-15 00:00:00
abstract::IDIOTYPY HAS BEEN STUDIED IN ANTIBODIES AGAINST A PROTEIN ANTIGEN: hen ovalbumin. Various fractions of antisera to hen ovalbumin have been compared from the standpoint of the idiotypic specificities found on the immunoglobulins that they contain. Idiotypic specificities were found to be common to (a) antibodies that w...
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.68.10.2616
更新日期:1971-10-01 00:00:00
abstract::The first essential step in protein photoreception is the capture and storage of energy from a photon. We have recently identified and isolated, from the purple photoautotrophic bacterium, Ectothiorhodospira halophila, a 13,000-dalton photoactive yellow protein (PYP) that has a photocycle with kinetics similar to sens...
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.86.17.6533
更新日期:1989-09-01 00:00:00
abstract::This paper describes the use of laminar flow of liquids in capillary systems to pattern the cell culture substrate, to perform patterned cell deposition, and to pattern the cell culture media. We demonstrate the patterning of the cell culture substrate with different proteins, the patterning of different types of cell...
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.96.10.5545
更新日期:1999-05-11 00:00:00