Abstract:
:The nucleotide sequence of 6.2 kb (1 kb = 10(3) base-pairs) of DNA that encompasses the earliest replicating portion of the amplified dihydrofolate reductase domains of CHOC 400 cells has been determined. Origin region DNA contains two AluI family repeats, a novel repetitive element (termed ORR-1), a TGGGT-rich region, and several homopurine/homopyrimidine and alternating purine/pyrimidine tracts, including an unusual cluster of simple repeating sequences composed of (G-C)5, (A-C)18, (A-G)21, (G)9, (CAGA)4, GAGGGAGAGAGGCAGAGAGGG, (A-G)27. Recombinant plasmids containing origin region sequences were examined for DNA structural conformations previously implicated in origin activation. Mung bean nuclease sensitivity assays for DNA unwinding elements show the preferred order of nuclease cleavage at neutral pH in supercoiled origin plasmids to be: (A-T)23 much greater than the (A-G) cluster much greater than (A)38 much greater than vector = (AATT)n. At acid pH, the hierarchy of cleavage preferences changes to: the (A-G) cluster much greater than (A-T)23 much greater than (AATT)n greater than vector = (A)38. A region of stably bent DNA was identified and shown not to be reactive in the mung bean nuclease unwinding assay at either acid or neutral pH. Intermolecular hybridization studies show that, in the presence of torsional stress at pH 5.2, the (A-G) cluster forms triple-stranded DNA. These results show that the origin region of an amplified chromosomal replicon contains a novel repetitive element and multiple sequence elements that facilitate DNA bending, DNA unwinding and the formation of intramolecular triple-stranded DNA.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Caddle MS,Lussier RH,Heintz NHdoi
10.1016/0022-2836(90)90008-Asubject
Has Abstractpub_date
1990-01-05 00:00:00pages
19-33issue
1eissn
0022-2836issn
1089-8638pii
0022-2836(90)90008-Ajournal_volume
211pub_type
杂志文章abstract::The nuclear pore complex (NPC) is strategically located at continuous junctions of the inner and outer nuclear membranes to catalyze macromolecular transport, without impending the diffusion of small molecules. In this paper, the structural plasticity of 4412 NPCs in isolated nuclear envelopes has been evaluated, util...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/s0022-2836(95)80050-6
更新日期:1995-04-28 00:00:00
abstract::The trimeric TolC protein of Escherichia coli comprises an outer membrane beta-barrel and a contiguous alpha-helical barrel projecting across the periplasm. This provides a single 140 A long pore for multidrug efflux and protein export. We have previously reported that trivalent cations such as hexammine cobalt can se...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.07.088
更新日期:2004-09-17 00:00:00
abstract::Using the binding of a nucleotide inhibitor (guanosine-3'-monophosphate) to a ribonuclease (ribonuclease Sa) as a model system, we show that the salt-dependence of the interaction arises due to specific ion binding at the site of nucleotide binding. The presence of specific ion-protein binding is concluded from a comb...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.12.018
更新日期:2005-02-25 00:00:00
abstract::Carboxypeptidase M (CPM), an extracellular glycosylphosphatidyl-inositol(GPI)-anchored membrane glycoprotein belonging to the CPN/E subfamily of "regulatory" metallo-carboxypeptidases, specifically removes C-terminal basic residues from peptides and proteins. Due to its wide distribution in human tissues, CPM is belie...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.02.058
更新日期:2004-04-23 00:00:00
abstract::BCL-XL is an anti-apoptotic BCL-2 family protein found both in the cytosol and bound to intracellular membranes. Structural studies of BCL-XL have advanced by deleting its hydrophobic C-terminus and adding detergents to enhance solubility. However, since the C-terminus is essential for function and detergents strongly...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2015.02.019
更新日期:2015-07-03 00:00:00
abstract::By examining F1 progeny of mutagenized Caenorhabditis elegans larvae, we recovered several dominant mutations which affect muscle structure. Five of these new mutations resulted in phenotypes unlike the previously recognized unc-54 and unc-15 dominant alleles. Mapping studies placed all five mutations in the same smal...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(84)90023-8
更新日期:1984-12-15 00:00:00
abstract::The lateral diffusion coefficient of fluorescent lipid analogues incorporated in four cubic phases of lipid-water systems was determined by the modulated fringe pattern photobleaching technique. In two of the phases, Q230 and Q224, whose structure is bicontinuous, the diffusion is almost as fast as in the fluid lipid ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1993.1051
更新日期:1993-01-20 00:00:00
abstract::pBR322 DNA, linearized by lysis of an oxolinic acid-treated culture of Escherichia coli strain DK6recA- (pBR322) with sodium dodecyl sulfate, was purified, treated with DNA polymerase in the presence of the four deoxynucleoside triphosphates, and ligated to DNA linkers containing the XhoI recognition sequence. Most of...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(85)90324-9
更新日期:1985-01-05 00:00:00
abstract::At low ionic strength, the SfiI restriction enzyme cleaved at similar rates both supercoiled and linear DNA with two SfiI sites and linear DNA with one SfiI site. For the substrates with two sites, the majority of the DNA was converted directly to products cut at both sites; the enzyme appears to bind to two sites bef...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1995.0506
更新日期:1995-09-29 00:00:00
abstract::An alternating adenine-thymine tract in a relaxed closed circular plasmid was found to become strongly reactive to osmium tetroxide in the presence of actinomycin D. We suggest that this is due to a local overwinding of the alternating tract as a result of positive supercoiling induced by intercalation of the antibiot...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(91)90555-k
更新日期:1991-05-20 00:00:00
abstract::The nucleotide sequence was obtained for the hypE gene in the cluster of structural and accessory genes required for the assembly and functioning of the membrane-bound, dimeric, (NiFe)hydrogenase in Azotobacter vinelandii. The hypE gene encodes a polypeptide of 341 amino acid residues which is rich in alanine, glycine...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1994.1149
更新日期:1994-02-11 00:00:00
abstract::The pathway for oxidative degradation of nicotine in Arthrobacter nicotinovorans includes two genetically and structurally unrelated flavoenzymes, 6-hydroxy-L-nicotine oxidase (6HLNO) and 6-hydroxy-D-nicotine oxidase, which act with absolute stereospecificity on the L- and D-forms, respectively, of 6-hydroxy-nicotine....
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2009.12.009
更新日期:2010-02-26 00:00:00
abstract::Activation of family A G-protein-coupled receptors involves a rearrangement of a conserved interhelical cytoplasmic hydrogen bond network between the E(D)RY motif on transmembrane helix 3 (H3) and residues on H6, which is commonly termed the cytoplasmic "ionic lock." Glu134(3.49) of the E(D)RY motif also forms an intr...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2008.05.022
更新日期:2008-07-18 00:00:00
abstract::Expansion of the polyglutamine (polyQ) region in the protein ataxin-3 is associated with spinocerebellar ataxia type 3, an inherited neurodegenerative disorder that belongs to the family of polyQ diseases. Increasing evidence indicates that protein aggregation and fibre formation play an important role in these pathol...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.09.065
更新日期:2004-12-03 00:00:00
abstract::Azaleucine is a naturally occurring amino acid antibiotic that can be incorporated into proteins by mimicking leucine. In spite of its highly toxic character, the contrast between the hydrophobic side-chain of leucine and the basic side-chain of azaleucine suggested a mechanism for rescuing certain mutants. We constru...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1993.1269
更新日期:1993-05-20 00:00:00
abstract::The crystal structure of the allosteric tetrameric hemoglobin from Scapharca inaequivalvis (HbII) has been determined in the carbonmonoxy liganded state using a combination of anomalous scattering and molecular replacement. The molecular model has been refined at 2.0 A resolution to a conventional R-factor of 0.173 an...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1995.0543
更新日期:1995-10-13 00:00:00
abstract::Previous work has shown that the α-tocopherol transfer protein (α-TTP) can bind to vesicular or immobilized phospholipid membranes. Revealing the molecular mechanisms by which α-TTP associates with membranes is thought to be critical to understanding its function and role in the secretion of tocopherol from hepatocyte...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2010.11.028
更新日期:2011-01-28 00:00:00
abstract::The expression of antibodies inside cells to ablate protein function has the potential for disease therapy and for target validation in functional genomics. However, due to inefficient expression or folding, only a few antibodies or antibody fragments, usually as single-chain Fv antibody fragments (scFv), bind their a...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.2002.5403
更新日期:2002-03-15 00:00:00
abstract::Previously we have shown that nuclear extracts from mouse cells contain a heterogeneous group of polypeptides (p65, p80, p90, p100) which form distinct DNA-protein complexes on the 18 base-pair sequence element (termed Sal-box), which constitutes the murine rDNA transcription termination signal. These distinct protein...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(92)90213-4
更新日期:1992-10-05 00:00:00
abstract::One mechanism for the repair of UV-induced DNA damage is the base excision repair pathway. The initial step in this pathway and the specificity for the type of damage that is to be repaired reside in DNA glycosylase/abasic (AP) lyases. Cleavage of the glycosyl bond of the 5' pyrimidine of a cyclobutane pyrimidine dime...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.3369
更新日期:2000-01-21 00:00:00
abstract::A gene library was constructed coding for all possible variants of two amino acids (101, 102) in a solvent-exposed surface return loop (alpha E-beta D) of Bacillus stearothermophilus L-lactate dehydrogenase (bsLDH). All but one of 38 enzyme variants examined were thermally stable and had native-like hydrodynamic prope...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1996.0626
更新日期:1996-11-22 00:00:00
abstract::Tumor suppressor p53 plays a central role in tumor suppression. p53 is the most frequently mutated gene in human cancer, and over half of human cancers contain p53 mutations. Majority of p53 mutations in cancer are missense mutations, leading to the expression of full-length mutant p53 (mutp53) protein. While the crit...
journal_title:Journal of molecular biology
pub_type: 杂志文章,评审
doi:10.1016/j.jmb.2017.03.030
更新日期:2017-06-02 00:00:00
abstract::The ctc gene of Bacillus subtilis is transcribed in vitro by the minor RNA polymerase holoenzyme forms, E sigma 37 and E sigma 32. To study the expression and regulation of ctc in vivo, we constructed operon and translational fusions of the ctc promoter region to the lacZ gene of Escherichia coli. Our results indicate...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(86)90449-3
更新日期:1986-10-20 00:00:00
abstract::The non-steroidal anti-estrogen tamoxifen [TAM] has been in clinical use over the last two decades as a potent adjunct chemotherapeutic agent for treatment of breast cancer. It has also been given prophylactically to women with a strong family history of breast cancer. However, tamoxifen treatment has also been associ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.2000.4071
更新日期:2000-09-15 00:00:00
abstract::In response to intracellular stress events ranging from starvation to pathogen invasion, the cell activates one or more forms of macroautophagy. The key event in these related pathways is the de novo formation of a new organelle called the autophagosome, which either surrounds and sequesters random portions of the cyt...
journal_title:Journal of molecular biology
pub_type: 杂志文章,评审
doi:10.1016/j.jmb.2017.01.006
更新日期:2017-02-17 00:00:00
abstract::Electron crystallography offers an increasingly viable alternative to X-ray crystallography for structure determination, especially for membrane proteins. The methodology has been developed and successfully applied to 2D crystals; however, well-ordered thin, 3D crystals are often produced during crystallization trials...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1998.2283
更新日期:1998-12-18 00:00:00
abstract::The ability of homologous chromosomes (or selected chromosomal loci) to pair specifically in the apparent absence of DNA breakage and recombination represents a prominent feature of eukaryotic biology. The mechanism of homology recognition at the basis of such recombination-independent pairing has remained elusive. A ...
journal_title:Journal of molecular biology
pub_type: 杂志文章,评审
doi:10.1016/j.jmb.2019.11.005
更新日期:2020-02-07 00:00:00
abstract::The secondary structure of bacterial RNase P RNA, a ribozyme responsible for the maturation of the 5' end of tRNAs, is well established on the basis of sequence comparison analysis. RNase P RNA secondary structures fall into two types, A and B, which share a common core formed by the assembly of two main folding domai...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1998.1797
更新日期:1998-06-19 00:00:00
abstract::In the presence of AMP-PCP (beta, gamma-methyleneadenosine 5'-triphosphate), a non-hydrolyzable analog of ATP, negative stain images of increased morphological detail indicate that the dynein arm, attached to ciliary doublet microtubules, is composed of subunits including a cape, an elongated body and a head. The arra...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(84)90127-x
更新日期:1984-03-05 00:00:00
abstract::In vivo, proteins occur in widely different physio-chemical environments, and, from in vitro studies, we know that protein structure can be very sensitive to environment. However, theoretical studies of protein structure have tended to ignore this complexity. In this paper, we have approached this problem by grouping ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1997.1498
更新日期:1998-02-20 00:00:00