Abstract:
:The bacterial TATAAT -10 region sequence was the first promoter element to be identified, but how it functions is still not clear. Because the duplex element is melted during initiation, the effects of substitutions were studied in both single-and double-strand contexts. Band-shift results were particularly unexpected in the context of melted DNA. The effect of the lac UV5-melted -10 region on polymerase binding was found to include a large sequence nonspecific contribution. Instead the dominant role of single-stranded -10 region nucleotides was in directing the isomerization of the RNA polymerase to its heparin resistant form. This role becomes minimal when the melting is extended beyond the -10 region to encompass the transcription start site, as in the final open complex. The duplex binding results are in agreement with previous reports that showed positions -12T and -11A are of primary importance for promoter recognition. Thus the consensus -10 region sequences function in two ways, both before full promoter melting. They stabilize initial polymerase binding via duplex interactions and subsequently as single-stranded DNA they promote enzyme isomerization to the functional form.
journal_name
Proc Natl Acad Sci U S Aauthors
Fenton MS,Gralla JDdoi
10.1073/pnas.161085798keywords:
subject
Has Abstractpub_date
2001-07-31 00:00:00pages
9020-5issue
16eissn
0027-8424issn
1091-6490pii
161085798journal_volume
98pub_type
杂志文章abstract::Tropical forest degradation emits carbon at a rate of approximately 0.5 Pgxy(-1), reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation aff...
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.0914471107
更新日期:2010-08-17 00:00:00
abstract::In experiments originally designed to examine selective turnover of methylated "caps" in renal mRNA, we observed that [3H]methyl label decayed from mRNA containing poly(A) with a half-life of 1-2 hr. (Caps are blocked, methylated mRNA sequences of the general structure m7GpppNm p(1 or 2)Np.). To distinguish between me...
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.73.8.2609
更新日期:1976-08-01 00:00:00
abstract::Cell cycle progression is tightly regulated by cyclin-dependent kinases (CDKs). The ankyrin-repeat protein p19INK4d functions as a key regulator of G1/S transition; however, its molecular mode of action is unknown. Here, we combine cell and structural biology methods to unravel the mechanism by which p19INK4d controls...
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.1719774115
更新日期:2018-03-27 00:00:00
abstract::Within the trimeric HIV-1 envelope (Env) spike, the first and second variable loops (V1V2 region) and the third variable loop (V3) of the gp120 subunit play dual roles in antibody recognition, because they contain neutralization epitopes and also participate in epitope masking. The spatial relationships between V1V2 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.1104840108
更新日期:2011-12-13 00:00:00
abstract::Preadipocytes can give rise to either white adipocytes or beige adipocytes. Owing to their distinct abilities in nutrient storage and energy expenditure, strategies that specifically promote "beiging" of adipocytes hold great promise for counterbalancing obesity and metabolic diseases. Yet, factors dictating the diffe...
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.1914553117
更新日期:2020-02-04 00:00:00
abstract::Histone methyltransferase G9a has critical roles in promoting cancer-cell growth and gene suppression, but whether it is also associated with the DNA damage response is rarely studied. Here, we report that loss of G9a impairs DNA damage repair and enhances the sensitivity of cancer cells to radiation and chemotherapeu...
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.1700694114
更新日期:2017-07-25 00:00:00
abstract::The "chlamydial anomaly," first coined by James Moulder, describes the inability of researchers to detect or purify peptidoglycan (PG) from pathogenic Chlamydiae despite genetic and biochemical evidence and antibiotic susceptibility data that suggest its existence. We recently detected PG in Chlamydia trachomatis by 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.1514026112
更新日期:2015-09-15 00:00:00
abstract::In some countries across the globe, tropical forest cover is increasing. The national-scale reforestation of Vietnam since 1992 is assumed to contribute to this recovery. It is achieved, however, by the displacement of forest extraction to other countries on the order of 49 (34-70) M m(3), or approximately 39% of the ...
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.0904942106
更新日期:2009-09-22 00:00:00
abstract::Oxygen-derived free radicals have been implicated in the pathogenesis of vasogenic edema and infarction caused by ischemia and reperfusion injury. In earlier studies, exogenously supplied liposome-entrapped CuZn superoxide dismutase (CuZn-SOD) ameliorated ischemic brain edema and infarction in rats following focal cer...
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.88.24.11158
更新日期:1991-12-15 00:00:00
abstract::Extracellular growth and differentiation factors induce changes in gene expression in the nucleus by initiating a series of protein associations that alter the subcellular localization of intracellular signaling proteins. Initial events involve receptor homo- or heterodimerization and subsequent recruitment of cytosol...
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.93.10.4604
更新日期:1996-05-14 00:00:00
abstract::We present here the complete genome sequence of a common avian clone of Pasteurella multocida, Pm70. The genome of Pm70 is a single circular chromosome 2,257,487 base pairs in length and contains 2,014 predicted coding regions, 6 ribosomal RNA operons, and 57 tRNAs. Genome-scale evolutionary analyses based on pairwise...
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.051634598
更新日期:2001-03-13 00:00:00
abstract::Four new members of the fibroblast growth factor (FGF) family, referred to as fibroblast growth factor homologous factors (FHFs), have been identified by a combination of random cDNA sequencing, data base searches, and degenerate PCR. Pairwise comparisons between the four FHFs show between 58% and 71% amino acid seque...
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.93.18.9850
更新日期:1996-09-03 00:00:00
abstract::Vertebrate hearing and balance are based in complex asymmetries of inner ear structure. Here, we identify retinoic acid (RA) as an extrinsic signal that acts directly on the ear rudiment to affect its compartmentalization along the anterior-posterior axis. A rostrocaudal wave of RA activity, generated by tissues surro...
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.1010547108
更新日期:2011-01-04 00:00:00
abstract::Replication through damaged sites in DNA requires in Escherichia coli the SOS stress-inducible DNA polymerase V (UmuC), which is specialized for lesion bypass. Homologs of the umuC gene were found on native conjugative plasmids, which often carry multiple antibiotic-resistant genes. MucB is a UmuC homolog present on 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.200361997
更新日期:2000-10-10 00:00:00
abstract::Three classes of heterogeneous nuclear RNA (HnRNA) alpha, beta, and gamma, with different chemical and physical properties, can be identified in the early sea urchin embryo by hybridization with poly(U). The relative amounts of these classes vary as a function of embryonic development. It is demonstrated here that the...
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.74.6.2217
更新日期:1977-06-01 00:00:00
abstract::Osteocalcin, a bone-specific protein and marker of the mature osteoblast, is expressed only in nonproliferating osteoblasts in a mineralizing extracellular matrix, while type I collagen is expressed in proliferating cells. The nuclear proteins encoded by the c-fos and c-jun protooncogenes are expressed during the prol...
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.87.24.9990
更新日期:1990-12-01 00:00:00
abstract::Esterase 6 is a polymorphic carboxylesterase (carboxylic-ester hydrolase, EC 3.1.1.1) localized to the reproductive tract of male Drosophila melanogaster and transferred to females at copulation. The reproductive fitness of males is strongly affected by temperature and the esterase 6 alleles (active versus null) that ...
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.79.9.2962
更新日期:1982-05-01 00:00:00
abstract::Phosphatase PP2A expression levels are positively correlated to the clinical severity of systemic lupus erythematosus (SLE) and IL17A cytokine overproduction, indicating a potential role of PP2A in controlling TH17 differentiation and inflammation. By generating a mouse strain with ablation of the catalytic subunit α ...
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.1807484116
更新日期:2019-01-15 00:00:00
abstract::Factor XI (plasma thromboplastin antecedent) deficiency is a blood coagulation abnormality occurring in high frequency in Ashkenazi Jews. Three independent point mutations that result in a blood coagulation abnormality have been identified in the factor XI gene of six unrelated Ashkenazi patients. These mutations eith...
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.86.20.7667
更新日期:1989-10-01 00:00:00
abstract::We have investigated the role of Sonic hedgehog (Shh) in the development of facial structures by depriving chicken embryos of the most anterior sources of this morphogen, including the prechordal plate and the anterior ventral endoderm of the foregut, before the onset of neural crest cell (NCC) migration to the first ...
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.0604751103
更新日期:2006-08-01 00:00:00
abstract::It has been a long-sought goal of quantum simulation to find answers to outstanding questions in condensed-matter physics. A famous example is finding the ground state and the excitations of the two-dimensional (2D) Hubbard model with strong repulsion below half-filling. This system is a doped antiferromagnet and is 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.2004268117
更新日期:2020-10-20 00:00:00
abstract::Translational stop codon readthrough occurs in organisms ranging from viruses to mammals and is especially prevalent in decoding Drosophila and viral mRNAs. Recoding of UGA, UAG, or UAA to specify an amino acid allows a proportion of the protein encoded by a single gene to be C-terminally extended. The extended produc...
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.2012793118
更新日期:2021-02-02 00:00:00
abstract::The three-dimensional structures of the inactive protein precursors (zymogens) of the serine, cysteine, aspartic, and metalloprotease classes of proteolytic enzymes are known. Comparisons of these structures with those of the mature, active proteases reveal that, in general, the preformed, active conformations of the ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.96.20.10968
更新日期:1999-09-28 00:00:00
abstract::Regulatory T cells (Treg) play critical roles in the modulation of immune responses to infectious agents. Further understanding of the factors that control Treg activation and expansion in response to pathogens is needed to manipulate Treg function in acute and chronic infections. Here we show that chronic, but not 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.1100213108
更新日期:2011-03-01 00:00:00
abstract::We have cloned a mutS homolog from Drosophila melanogaster called spellchecker1 (spel1) and have constructed spel1 mutant flies. MutS proteins promote the correction of DNA mismatches and serve important roles in DNA replication, recombination, and repair. The spel1 gene belongs to a subfamily of mutS first characteri...
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.96.6.2964
更新日期:1999-03-16 00:00:00
abstract::Thermal macrophysiology is an established research field that has led to well-described patterns in the global structuring of climate adaptation and risk. However, since it was developed primarily in animals, we lack information on how general these patterns are across organisms. This is alarming if we are to understa...
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.1918162117
更新日期:2020-06-16 00:00:00
abstract::High-accuracy ab initio folding has remained an elusive objective despite decades of effort. To explore the folding landscape of villin headpiece subdomain HP35, we conducted two sets of replica exchange molecular dynamics for 200 ns each and three sets of conventional microsecond-long molecular dynamics simulations, ...
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.0608432104
更新日期:2007-03-20 00:00:00
abstract::Human Creutzfeldt-Jakob disease (CJD) and similar neurodegenerative diseases such as sheep scrapie are caused by a variety of related infectious agents. They are associated with abnormal host prion protein (PrP), which is assessed by limited proteolysis to yield resistant PrP bands (PrP-res). Although PrP-res has been...
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.0400158101
更新日期:2004-06-08 00:00:00
abstract::The influenza virus hemagglutinin polypeptides, HA1 and HA2, have been purified by gel filtration in the presence of sodium dodecyl sulfate from a vaccine preparation of the recombinant strain Heq1N2. Use of this technique for purification of the hemagglutinin polypeptides eliminated the need for proteolytic agents fo...
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.73.1.238
更新日期:1976-01-01 00:00:00
abstract::L203 and L227 are mouse monoclonal antibodies specific for human HLA-DR antigens. Their reactivity with multiple, structurally different, HLA-DR antigens was examined by using radioiodinated human lymphoblastoid cells and cell lines, heterozygous or homozygous at the HLA-D locus. Antibody L203 precipitates DR antigens...
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.79.8.2658
更新日期:1982-04-01 00:00:00