Direct visualization of the binding of c-Myc/Max heterodimeric b-HLH-LZ to E-box sequences on the hTERT promoter.


:Myc and Max belong to the b-HLH-LZ family of transcription factors. Heterodimerization between Myc and Max or homodimerization of Max allows these proteins to bind their cognate DNA sequence known as the E-box (CACGTG). Recent evidence has suggested that the c-Myc/Max heterodimeric b-HLH-LZ could interact to form a head-to-tail dimer of dimers and induce complex topologies such as loops in promoters containing more than one E-box sequence. In an attempt to shed light on this hypothesis, the interaction between the heterodimeric b-HLH-LZ of c-Myc/Max and a fragment of the hTERT promoter containing two E-box sequences was studied by atomic force microscopy. Specific binding events were observed at both E-box sites with equal probabilities. In accordance with previous results obtained by EMSA, we observed that the specific binding of the c-Myc/Max b-HLH-LZ bends the promoter. However no looping could be observed in a wide range of concentration encompassing the Ka (association constant) of the putative tetramer and the Ka for the specific binding of the heterodimer. In contrast, experiments performed with a mandatory c-Myc/Max b-HLH-LZ tetramer incubated with the hTERT promoter fragment allowed for the visualization of loops and cross-linked DNA strands originating from specific binding. Altogether, our results indicate that the c-Myc/Max b-HLH-LZ dimer binds specifically and equally to both E-box sites of the hTERT promoter and induces a significant bending of the promoter and that the suggested oligomerization of the c-Myc/Max heterodimeric b-HLH-LZ, if existing, is most likely too weak to induce the formation of a loop in a promoter.






Lebel R,McDuff FO,Lavigne P,Grandbois M




Has Abstract


2007-09-11 00:00:00












  • Structural basis for induced fit mechanisms in DNA recognition by the Pdx1 homeodomain.

    abstract::Pancreatic and duodenal homeobox 1 (Pdx1) is a homeodomain transcription factor belonging to the ParaHox family. Pdx1 plays an essential role in pancreatic endocrine and exocrine cell development and maintenance of adult islet beta-cell function. Mutations in the human pdx1 gene are linked to an early onset form of no...


    pub_type: 杂志文章


    authors: Longo A,Guanga GP,Rose RB

    更新日期:2007-03-20 00:00:00

  • Mitochondrial NADH-ubiquinone reductase: complementary DNA sequences of import precursors of the bovine and human 24-kDa subunit.

    abstract::The 24-kDa subunit of mitochondrial NADH-ubiquinone reductase (complex I) is an iron-sulfur protein that is present in the flavoprotein or NADH dehydrogenase II subcomplex. It is a nuclear gene product and is imported into the organelle. A group of human patients with mitochondrial myopathy have been shown to have red...


    pub_type: 杂志文章


    authors: Pilkington SJ,Walker JE

    更新日期:1989-04-18 00:00:00

  • Transfer of band 3, the erythrocyte anion transporter, between phospholipid vesicles and cells.

    abstract::Band 3, the anion transport protein of human erythrocyte membranes, can be transferred from cells to liposomes and from liposomes back to cell membranes, retaining function and native orientation. After incubation with cells, sonicated phosphatidylcholine vesicles bind a transmembrane protein that comigrates with band...


    pub_type: 杂志文章


    authors: Newton AC,Cook SL,Huestis WH

    更新日期:1983-12-20 00:00:00

  • Xenopus laevis hemoglobin and its hybrids with hemoglobin A+.

    abstract::Isolated alpha and beta chains from Xenopus laevis hemoglobin have been purified. The isolation procedure yields native alpha chains whose functional behavior has been characterized and compared with that of human alpha chains. Isolated beta chains in the presence of oxygen are characterized by low stability, and henc...


    pub_type: 杂志文章


    authors: Condò SG,Giardina B,Bellelli A,Brunori M

    更新日期:1987-10-20 00:00:00

  • Glutamate 189 of the D1 polypeptide modulates the magnetic and redox properties of the manganese cluster and tyrosine Y(Z) in photosystem II.

    abstract::Recent models for water oxidation in photosystem II postulate that the tyrosine Y(Z) radical, Y(Z)(*), abstracts both an electron and a proton from the Mn cluster during one or more steps in the catalytic cycle. This coupling of proton- and electron-transfer events is postulated to provide the necessary driving force ...


    pub_type: 杂志文章


    authors: Debus RJ,Campbell KA,Pham DP,Hays AM,Britt RD

    更新日期:2000-05-30 00:00:00

  • DNA ligase I from Saccharomyces cerevisiae: physical and biochemical characterization of the CDC9 gene product.

    abstract::Genetic studies have previously demonstrated that the Saccharomyces cerevisiae CDC9 gene product, which is functionally homologous to mammalian DNA ligase I, is required for DNA replication and is also involved in DNA repair and genetic recombination. In the present study we have purified the yeast enzyme. When measur...


    pub_type: 杂志文章


    authors: Tomkinson AE,Tappe NJ,Friedberg EC

    更新日期:1992-12-01 00:00:00

  • Indolequinone inhibitors of NRH:quinone oxidoreductase 2. Characterization of the mechanism of inhibition in both cell-free and cellular systems.

    abstract::We describe a series of indolequinones as efficient mechanism-based inhibitors of NRH:quinone oxidoreductase 2 (NQO2) for use either in cellular or cell-free systems. Compounds were designed to be reduced in the active site of the enzyme leading to loss of a substituted phenol leaving group and generation of a reactiv...


    pub_type: 杂志文章


    authors: Yan C,Dufour M,Siegel D,Reigan P,Gomez J,Shieh B,Moody CJ,Ross D

    更新日期:2011-08-09 00:00:00

  • Catalysis of RNA cleavage by a ribozyme derived from the group I intron of Anabaena pre-tRNA(Leu).

    abstract::In the cyanobacterium Anabaena PCC7120, the precursor to tRNA(Leu) contains a 249-nucleotide group I intron that undergoes efficient self-splicing in vitro. By deleting the 5' and 3' splice sites, this intron has now been converted to an RNA enzyme that uses a guanosine nucleophile to cleave substrate RNAs (S) with mu...


    pub_type: 杂志文章


    authors: Zaug AJ,Dávila-Aponte JA,Cech TR

    更新日期:1994-12-13 00:00:00

  • Combined N- and C-terminal truncation of human apolipoprotein A-I yields a folded, functional central domain.

    abstract::A combined N- and C-terminal truncation variant of human apolipoprotein A-I (apoA-I) was designed, expressed in Escherichia coli, isolated, and characterized. Hydrodynamic experiments yielded a weight average molecular weight of 34000, indicating apoA-I-(44-186) exists in solution predominantly as a dimer. An axial ra...


    pub_type: 杂志文章


    authors: Beckstead JA,Block BL,Bielicki JK,Kay CM,Oda MN,Ryan RO

    更新日期:2005-03-22 00:00:00

  • Reversible unfolding of ribosomal protein E-L30: an NMR study.

    abstract::Ribosomal protein E-L30 unfolds reversibly at pH values between 7.0 and 4.5. Unfolding of the protein involves a fast and a slow equilibrium, which depend on the degree of protonation of His19 and His33. Both the fast equilibrium between protonated and deprotonated histidines and the slow equilibrium between folded an...


    pub_type: 杂志文章


    authors: van de Ven FJ,Hilbers CW

    更新日期:1987-08-25 00:00:00

  • Energetics of internal GU mismatches in ribooligonucleotide helixes.

    abstract::Thermodynamic parameters of helix formation were measured spectroscopically for 16 oligoribonucleotides containing either internal GU mismatches or the corresponding AU pairs. Internal GU mismatches stabilize each helix, but not as much as the corresponding AU pairs. The differences in the enthalpy and entropy changes...


    pub_type: 杂志文章


    authors: Sugimoto N,Kierzek R,Freier SM,Turner DH

    更新日期:1986-09-23 00:00:00

  • 1H, 15N, 13C, and 13CO assignments of human interleukin-4 using three-dimensional double- and triple-resonance heteronuclear magnetic resonance spectroscopy.

    abstract::The assignment of the 1H, 15N, 13CO, and 13C resonances of recombinant human interleukin-4 (IL-4), a protein of 133 residues and molecular mass of 15.4 kDa, is presented based on a series of 11 three-dimensional (3D) double- and triple-resonance heteronuclear NMR experiments. These studies employ uniformly labeled 15N...


    pub_type: 杂志文章


    authors: Powers R,Garrett DS,March CJ,Frieden EA,Gronenborn AM,Clore GM

    更新日期:1992-05-05 00:00:00

  • Dehydroquinate synthase: the use of substrate analogues to probe the early steps of the catalyzed reaction.

    abstract::The early steps of the proposed mechanistic pathway for dehydroquinate synthase have been probed with a series of substrate analogues. These analogues, 3-9, are structurally prohibited from undergoing the beta-elimination of inorganic phosphate that represents the committed step in the conversion of the substrate 3-de...


    pub_type: 杂志文章


    authors: Bender SL,Widlanski T,Knowles JR

    更新日期:1989-09-19 00:00:00

  • High-spin states (S >/= 5/2) of the photosystem II manganese complex.

    abstract::The Mn4 complex which is involved in water oxidation in photosystem II (PSII) is known to exhibit two types of EPR signals in the S2 state, one of the five redox states of the enzyme cycle: either a multiline signal (S = 1/2) or a signal at g = 4.1 (S = 3/2 or S= 5/2). The S = 1/2 state can be converted to that respon...


    pub_type: 杂志文章


    authors: Boussac A,Un S,Horner O,Rutherford AW

    更新日期:1998-03-24 00:00:00

  • Calcium modulates the photoassembly of photosystem II (Mn)4-clusters by preventing ligation of nonfunctional high-valency states of manganese.

    abstract::The requirement for Ca2+ in the Mn(2+)-dependent photoactivation of oxygen evolution was re-evaluated using 17 kDa/24 kDa-less photosystem II (PSII) membranes depleted of (Mn)4-clusters by NH2OH extraction. At optimum conditions (1 mM Mn2+/10 microM 2,6-dichlorphenolindophenol (DCIP)/20 mM Ca2+), the light-induced inc...


    pub_type: 杂志文章


    authors: Chen C,Kazimir J,Cheniae GM

    更新日期:1995-10-17 00:00:00

  • Analysis of DNA-dependent protein kinase-mediated DNA end joining by two-photon fluorescence cross-correlation spectroscopy.

    abstract::Nonhomologous end joining (NHEJ) is the primary mechanism by which mammalian cells repair DNA double-strand breaks (DSBs). Proteins known to play a role in NHEJ include the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), the Ku 70/Ku 80 heterodimer (Ku), XRCC4, and DNA ligase IV. One of the main roles of th...


    pub_type: 杂志文章


    authors: Merkle D,Block WD,Yu Y,Lees-Miller SP,Cramb DT

    更新日期:2006-04-04 00:00:00

  • Interaction of Vitreoscilla hemoglobin with membrane lipids.

    abstract::The interaction of the recombinant hemoglobin from Vitreoscilla sp. (VHb) with the bacterial membrane of Escherichia coli cells has been investigated by measuring the propensity of VHb to interact with monolayers formed by natural bacterial phosholipids. The measurements showed that the protein is capable of penetrati...


    pub_type: 杂志文章


    authors: Rinaldi AC,Bonamore A,Macone A,Boffi A,Bozzi A,Di Giulio A

    更新日期:2006-04-04 00:00:00

  • Human alpha- to zeta-thrombin cleavage occurs with neutrophil cathepsin G or chymotrypsin while fibrinogen clotting activity is retained.

    abstract::Human neutrophil cathepsin G or bovine chymotrypsin proteolytically cleaved human alpha-thrombin at the B-chain Trp148-Thr149 bond generating a new form, zeta-thrombin. While incubation of alpha-thrombin with cathepsin G at pH 7.4 and 37 degrees C resulted in a partial loss of fibrinogen clotting activity, 86 +/- 13% ...


    pub_type: 杂志文章


    authors: Brezniak DV,Brower MS,Witting JI,Walz DA,Fenton JW 2nd

    更新日期:1990-04-10 00:00:00

  • Solution structure of N-(2-deoxy-D-erythro-pentofuranosyl)urea frameshifts, one intrahelical and the other extrahelical, by nuclear magnetic resonance and molecular dynamics.

    abstract::The presence of a N-(2-deoxy-D-erythro pentofuranosyl)urea (henceforth referred to as deoxyribosylurea) residue, ring fragmentation product of a thymine, in a frameshift situation in the sequence 5'd(AGGACCACG).d(CGTGGurTCCT) has been studied by 1H and 31P nuclear magnetic resonance and molecular dynamics. At equilibr...


    pub_type: 杂志文章


    authors: Gervais V,Cognet JA,Guy A,Cadet J,Téoule R,Fazakerley GV

    更新日期:1998-01-27 00:00:00

  • Prediction of inhibitor binding free energies by quantum neural networks. Nucleoside analogues binding to trypanosomal nucleoside hydrolase.

    abstract::A computational method has been developed to predict inhibitor binding energy for untested inhibitor molecules. A neural network is trained from the electrostatic potential surfaces of known inhibitors and their binding energies. The algorithm is then able to predict, with high accuracy, the binding energy of unknown ...


    pub_type: 杂志文章


    authors: Braunheim BB,Miles RW,Schramm VL,Schwartz SD

    更新日期:1999-12-07 00:00:00

  • Sequences of B-chain/domain 1-10/1-9 of insulin and insulin-like growth factor 1 determine their different folding behavior.

    abstract::Although insulin and insulin-like growth factor-1 (IGF-1) belong to one family, insulin folds into one thermodynamically stable structure, while IGF-1-folds into two thermodynamically stable structures (native and swap forms). We have demonstrated previously that the bifurcating folding behavior of IGF-1 is mainly con...


    pub_type: 杂志文章


    authors: Chen Y,You Y,Jin R,Guo ZY,Feng YM

    更新日期:2004-07-20 00:00:00

  • Structural RNA mimetics: N3'-->P5' phosphoramidate DNA analogs of HIV-1 RRE and TAR RNA form A-type helices that bind specifically to Rev and Tat-related peptides.

    abstract::An attractive strategy for the development of anti-retroviral drugs is the exploration of compounds that mimic RNA control regions of the viral genome and act as "decoys" to sequester viral gene regulatory proteins. Decoys consisting of RNA, however, are chemically unstable and readily degraded by cellular nucleases. ...


    pub_type: 杂志文章


    authors: Rigl CT,Lloyd DH,Tsou DS,Gryaznov SM,Wilson WD

    更新日期:1997-01-21 00:00:00

  • Purification and properties of nuclease SP.

    abstract::Single-strand-specific nucleases are a diverse and important group of enzymes that are able to cleave a variety of DNA structures present in duplex molecules. Nuclease SP, an enzyme from spinach, has been purified to apparent homogeneity, allowing for the unambiguous characterization of a number of its physical proper...


    pub_type: 杂志文章


    authors: Strickland JA,Marzilli LG,Puckett JM Jr,Doetsch PW

    更新日期:1991-10-08 00:00:00

  • Correlations of crystal structures of DNA oligonucleotides with enantioselective recognition by Rh(phen)2phi3+: probes of DNA propeller twisting in solution.

    abstract::Rh(phen)2phi3+ (phen = 1,10-phenanthroline; phi = 9,10-phenanthrenequinone diimine) avidly binds to DNA via intercalation from the major groove and upon photoactivation produces strand scission with single base 5' asymmetry. Enantiomers of Rh(phen)2phi3+, which lack hydrogen-bonding substituents in ancillary positions...


    pub_type: 杂志文章


    authors: Campisi D,Morii T,Barton JK

    更新日期:1994-04-12 00:00:00

  • Solution structure of the second extracellular loop of human thromboxane A2 receptor.

    abstract::Thromboxane A(2) receptor (TP receptor), a prostanoid receptor, belongs to the G protein-coupled receptor family, composed of three intracellular loops and three extracellular loops connecting seven transmembrane helices. The highly conserved extracellular domains of the prostanoid receptors were found in the second e...


    pub_type: 杂志文章


    authors: Ruan KH,So SP,Wu J,Li D,Huang A,Kung J

    更新日期:2001-01-09 00:00:00

  • Structural and dynamic aspects of binding of a prototype lexitropsin to the decadeoxyribonucleotide d(CGCAATTGCG)2 deduced from high-resolution 1H NMR Studies.

    abstract::Structural and dynamic properties of the self-complementary decadeoxyribonucleotide d(CGCAATTGCG)2 and the interaction between a prototype lexitropsin, or information-reading oligopeptide, and the decadeoxyribonucleotide are deduced by using high-resolution 1H NMR techniques. The nonexchangeable and imino proton reson...


    pub_type: 杂志文章


    authors: Lee M,Chang DK,Hartley JA,Pon RT,Krowicki K,Lown JW

    更新日期:1988-01-12 00:00:00

  • Using saturation-recovery EPR to measure distances in proteins: applications to photosystem II.

    abstract::The stable tyrosine radical YD. (tyrosine 160 in the D2 polypeptide) in photosystem II (PSII) exhibits nonexponential electron spin-lattice relaxation transients at low temperature. As previously reported, the tetranuclear Mn complex in PSII significantly enhances the spin-lattice relaxation of YD.. However, in Mn-dep...


    pub_type: 杂志文章


    authors: Hirsh DJ,Beck WF,Innes JB,Brudvig GW

    更新日期:1992-01-21 00:00:00

  • Hydrolysis of proteins using dipeptidyl aminopeptidases: analysis of the N-terminal portion of spinach plastocyanin.

    abstract::The exopeptidases dipeptidyl aminopeptidases I and IV were used to hydrolyze the N-terminal portion of spinach plastocyanin to dipeptides. The enzymes were used individually as well as in a mixture and the dipeptides were analyzed by combined gas chromatography-mass spectrometry. Data are presented for native plastocy...


    pub_type: 杂志文章


    authors: Seifert WE Jr,Caprioli RM

    更新日期:1978-02-07 00:00:00

  • Multiple conformations of NAD and NADH when bound to human cytosolic and mitochondrial aldehyde dehydrogenase.

    abstract::Crystallographic analysis revealed that the nicotinamide ring of NAD can bind with multiconformations to aldehyde dehydrogenase (ALDH) (Ni, L., Zhou, J., Hurley, T. D., and Weiner, H. (1999) Protein Sci. 8, 2784-2790). Electron densities can be defined for two conformations, neither of which appears to be compatible w...


    pub_type: 杂志文章


    authors: Hammen PK,Allali-Hassani A,Hallenga K,Hurley TD,Weiner H

    更新日期:2002-06-04 00:00:00

  • Kinetic and mechanistic studies of the NO*-mediated oxidation of oxymyoglobin and oxyhemoglobin.

    abstract::The second-order rate constants for the reactions between nitrogen monoxide and oxymyoglobin or oxyhemoglobin, determined by stopped-flow spectroscopy, increase with increasing pH. At pH 7.0 the rates are (43.6 +/- 0.5) x 10(6) M(-1) x s(-1) for oxymyoglobin and (89 +/- 3) x 10(6) M(-1) x s(-1) for oxyhemoglobin (per ...


    pub_type: 杂志文章


    authors: Herold S,Exner M,Nauser T

    更新日期:2001-03-20 00:00:00