Abstract:
:The low-angle X-ray diffraction pattern from Lethocerus flight muscle fibres was recorded in rigor or under two conditions that modify crossbridge structure and behaviour, aqueous adenylylimidodiphosphate (AMPPNP) and AMPPNP + calcium in an ethylene glycol-water mixture. The effects on the 38.7 nm layer-line peaks (hk.6) of the diffraction patterns were studied in detail. In aqueous AMPPNP at room temperature, a condition in which rigor tension drops to half without loss of stiffness, the peaks remained nearly as intense as in rigor except for the 10.6, which dropped to half. In 20% (v/v) ethylene glycol-AMPPNP + 100 microM-Ca2+ at 23 degrees C (gly + pnp + Ca), a condition which removed muscle tension but left stiffness close to the rigor value, the 10.6 and 11.6 peaks greatly decreased but the 31.6 remained relatively high. The 14.5 nm meridional peak (00.16) became stronger on addition of AMPPNP and again on adding glycol + calcium. Considered in terms of constructively interfering filaments and crossbridges, the X-ray data indicated a transfer of diffracting crossbridge mass towards the thick filament as relaxation proceeds. We compared the X-ray diffraction patterns and crossbridge structure seen with electron microscopy (EM) under the same chemical conditions. EM and X-ray observations were mutually quite consistent overall. However, X-ray data indicated that more crossbridge mass was stereospecifically related to actin before fixation in the partially relaxed state (gly + pnp + Ca) than was suggested by the disordered crossbridge profiles seen by EM. We conclude that myosin heads at the start of the power stroke may both be closely related to their thick filament origins and form actin-determined attachments to the thin filament.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Tregear RT,Wakabayashi K,Tanaka H,Iwamoto H,Reedy MC,Reedy MK,Sugi H,Amemiya Ydoi
10.1016/0022-2836(90)90152-Csubject
Has Abstractpub_date
1990-07-05 00:00:00pages
129-41issue
1eissn
0022-2836issn
1089-8638pii
0022-2836(90)90152-Cjournal_volume
214pub_type
杂志文章abstract::Mycobacterium tuberculosis (Mtb), the intracellular pathogen that infects macrophages primarily, is the causative agent of the infectious disease tuberculosis in humans. The Mtb genome encodes at least six epoxide hydrolases (EHs A to F). EHs convert epoxides to trans-dihydrodiols and have roles in drug metabolism as ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2008.06.030
更新日期:2008-09-12 00:00:00
abstract::The CCAAT/enhancer-binding protein beta (C/EBPbeta) is a critical transcription factor that regulates gene expression during numerous biological processes, including differentiation, metabolism, homeostasis, proliferation, tumorigenesis, inflammation, and apoptosis. In this study, interactions between C/EBPbeta and ei...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2009.06.055
更新日期:2009-08-28 00:00:00
abstract::We present a calculation of the relative changes in binding free energy between the complex of ribonuclease T1 (RNase Tr) with its inhibitor 2'-guanosine monophosphate (2'GMP) and that of RNase T1-2'-adenosine monophosphate (2'AMP) by means of a thermodynamic perturbation method implemented with molecular dynamics. Us...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(90)90315-D
更新日期:1990-03-05 00:00:00
abstract::An accurate three-dimensional structure is known for papain (1.65 A resolution) and actinidin (1.7 A). A detailed comparison of these two structures was performed to determine the effect of amino acid changes on the conformation. It appeared that, despite only 48% identity in their amino acid sequence, different cryst...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(85)90348-1
更新日期:1985-03-20 00:00:00
abstract::Translation initiation of human Bip mRNA is directed by an internal ribosomal entry site (IRES) located in the 5' non-translated region. No trans-acting factor possibly involved in this process has as of yet been identified. For the encephalomyocarditis virus and other picornaviruses, polypyrimidine tract-binding prot...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.2000.4179
更新日期:2000-11-24 00:00:00
abstract::It has been well established that a single amino acid sequence can give rise to several conformationally distinct amyloid states. The extent to which amyloid structures formed within the same sequence are different, however, remains unclear. To address this question, we studied two amyloid states (referred to as R- an...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2010.05.051
更新日期:2010-07-23 00:00:00
abstract::Within the larger ABC superfamily of ATPases, ABCF family members eEF3 in Saccharomyces cerevisiae and EttA in Escherichia coli have been found to function as ribosomal translation factors. Several other ABCFs including biochemically characterized VgaA, LsaA and MsrE confer resistance to antibiotics that target the pe...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2018.12.013
更新日期:2019-08-23 00:00:00
abstract::A large survey of reliably known structures supports the hypothesis that protein loops can behave like elastic strings, and has enabled a parameter describing the entropically generated tensions to be determined. Such tensions may be of major importance in the folding process; here they are discussed mainly in the con...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/S0022-2836(05)80334-1
更新日期:1990-11-20 00:00:00
abstract::Drosophila alcohol dehydrogenase (DADH) is an NAD+-dependent enzyme that catalyzes the oxidation of alcohols to aldehydes/ketones and that is also able to further oxidize aldehydes to their corresponding carboxylic acids. The structure of the ternary enzyme-NADH-acetate complex of the slow alleloform of Drosophila mel...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.10.028
更新日期:2005-01-21 00:00:00
abstract::Escherichia coli nitroreductase is a flavoprotein that reduces a variety of quinone and nitroaromatic substrates. Its ability to convert relatively non-toxic prodrugs such as CB1954 (5-[aziridin-1-yl]-2,4-dinitrobenzamide) into highly cytotoxic derivatives has led to interest in its potential for cancer gene therapy. ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.2001.4653
更新日期:2001-05-25 00:00:00
abstract::The methylation-dependent restriction endonuclease McrBC from Escherichia coli K12 cleaves DNA containing two R(m)C dinucleotides separated by about 40 to 2000 base-pairs. McrBC is unique in that cleavage is totally dependent on GTP hydrolysis. McrB is the GTP binding and hydrolyzing subunit, whereas MrC stimulates it...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.3103
更新日期:1999-09-24 00:00:00
abstract::Assembly of normally soluble proteins into ordered aggregates, known as amyloid fibrils, is a cause or associated symptom of numerous human disorders, including Alzheimer's and the prion diseases. Here, we test the ability of discontinuous molecular dynamics (DMD) simulations based on PRIME20, a new intermediate-resol...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2011.12.038
更新日期:2012-03-02 00:00:00
abstract::Drosophila projectin is an extremely large protein found within the muscle sarcomeric unit, parallel with the actin and myosin filaments. Projectin has been suggested as the elastic component of C-filaments in insect indirect flight muscles, which is consistent with its localization from the Z band to the tip of the A...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.2001.5115
更新日期:2001-11-09 00:00:00
abstract::X-ray data have been recorded to 1.0 A resolution from a crystal of Fusarium solani cutinase using synchrotron radiation and an imaging-plate scanner. The anisotropic treatment of thermal motion led to a fivefold increase in accuracy and to a considerable quality improvement in the electron density maps with respect t...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1997.1000
更新日期:1997-05-16 00:00:00
abstract::The dielectric constants of sickle cell hemoglobin were determined before and after gelation. The dielectric properties of oxy and deoxy sickle cell hemoglobin in solution are nearly identical to those of oxy and deoxy hemoglobin A. Only in the gel state did deoxy sickle cell hemoglobin display dielectric behavior dif...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/s0022-2836(83)80307-6
更新日期:1983-08-15 00:00:00
abstract::The bacteriophage P1 recombinase Cre mediates site-specific recombination between loxP sites. The loxP site consists of two 13 base-pair inverted repeats separated by an eight base-pair spacer region. When DNA containing the loxP site is incubated with Cre, specific cleavages occur within the spacer region, creating a...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(85)90224-4
更新日期:1985-02-05 00:00:00
abstract::Using a human non-immune phage library comprising more than 10(9) functional human antibody specificities in Fab format, we have been able to select a set of eight monoclonal Fabs targeted against diverse epitopes of the ectodomain of gp41 from HIV-1. The antigens used for panning the antibodies comprised two soluble,...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2005.09.044
更新日期:2005-11-11 00:00:00
abstract::The formation of two-dimensional crystals of the membrane-bound enzyme microsomal glutathione transferase is sensitive to fractional changes in the lipid-to-protein ratio. Variation of this parameter results in crystal polymorphism. The projection structure of a p6 crystal form of the enzyme has been determined by the...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.2683
更新日期:1999-04-30 00:00:00
abstract::Genetic circuits, composed of complex networks of interacting molecular machines, enable living systems to sense their dynamic environments, perform computation on the inputs, and formulate appropriate outputs. By rewiring and expanding these circuits with novel parts and modules, synthetic biologists have adapted liv...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2016.02.018
更新日期:2016-02-27 00:00:00
abstract::Ubiquitination refers to the covalent addition of ubiquitin (Ub) to substrate proteins or other Ub molecules via the sequential action of three enzymes (E1, E2, and E3). Recent advances in mass spectrometry proteomics have made it possible to identify and quantify Ub linkages in biochemical and cellular systems. We us...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2011.03.011
更新日期:2011-05-06 00:00:00
abstract::The cytokine, interleukin-1beta (IL-1beta), adopts a beta-trefoil fold. It is known to be much slower folding than similarly sized proteins, despite having a low contact order. Proteins are sufficiently well designed that their folding is not dominated by local energetic traps. Therefore, protein models that encode on...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2005.11.074
更新日期:2006-03-31 00:00:00
abstract::Pre-steady-state chemical quenched-flow techniques were used to study DNA unwinding catalyzed by Escherichia coli UvrD helicase (helicase II), a member of the SF1 helicase superfamily. Single turnover experiments, with respect to unwinding of a DNA oligonucleotide, were used to examine the DNA substrate and UvrD conce...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.3185
更新日期:1999-11-05 00:00:00
abstract::Cytochrome c6from the unicellular green alga Scenedesmus obliquus was sequenced, crystallized in its reduced and oxidized state and the three-dimensional structure of the protein in both redox states was determined by X-ray crystallography. Reduced cytochrome c6crystallized as a monomer in the space group P 21212, whe...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.2944
更新日期:1999-07-30 00:00:00
abstract::With a rapidly growing pool of known tertiary structures, the importance of protein structure comparison parallels that of sequence alignment. We have developed a novel algorithm (DALI) for optimal pairwise alignment of protein structures. The three-dimensional co-ordinates of each protein are used to calculate residu...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1993.1489
更新日期:1993-09-05 00:00:00
abstract::A combination of Monte Carlo simulated annealing and energy minimization was utilized to determine the conformation of the antifreeze protein from the fish winter flounder. It was found from the energy-optimized structure that the hydroxyl groups of its four threonine residues, i.e. Thr2, Thr13, Thr24, Thr35, are alig...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(92)90666-8
更新日期:1992-01-20 00:00:00
abstract::GTP and Ca2+, two well-known modulators of intracellular signaling pathways, control a structural/functional switch between two vital and mutually exclusive activities, cross-linking and Galpha activity, in the same enzyme. The enzyme, a brain-derived tissue-type transglutaminase (TGase), was recently cloned by us in ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1998.2052
更新日期:1998-10-02 00:00:00
abstract::Three ribosomal RNA mutations conferring resistance to the antibiotic kasugamycin were isolated using a strain of Escherichia coli in which all of the rRNA is transcribed from a plasmid-encoded rrn operon. The mutations, A794G, G926A, and A1519C, mapped to universally conserved sites in the 16 S RNA gene. Site-directe...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.3160
更新日期:1999-10-15 00:00:00
abstract::We have isolated and sequenced a cloned complementary DNA insert complementary to the messenger RNA of a cytoplasmic actin expressed in human epidermal cells. This provides the first cytoplasmic actin complementary DNA sequence for a vertebrate organism. The actin amino acid sequence predicted from this complementary ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(83)90117-1
更新日期:1983-02-05 00:00:00
abstract::Intramembrane enzymes are often difficult for biochemical characterization. Human vitamin K epoxide reductase (VKOR) is the target of warfarin. However, this intramembrane enzyme becomes insensitive to warfarin inhibition in vitro, preventing the characterization of inhibition kinetics for decades. Here we employ stru...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2020.05.009
更新日期:2020-08-21 00:00:00
abstract::Sequences flanking the protein-coding regions of 15 of the 17 to 20 actin genes in the cellular slime mold Dictyostelium discoidium have been determined. Comparison of sequences among genes shows that they contain extensive homologies at both the 5' and 3' ends of the coding regions. On the basis of these homologies, ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(85)90003-8
更新日期:1985-06-05 00:00:00