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::The cleavage site of the T4 prohead protease in gene product 68 of bacteriophage T4 has been determined by direct protein sequencing. It is located close to the carboxy-terminal end of a predicted alpha-helix in the sequence Asn-Val-Glu-Ala between the Glu and Ala residues. Secondary structure seems to be more importa...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(85)90138-x
更新日期:1985-12-05 00:00:00
abstract::The presence of certain local structural elements in superhelical DNA, such as cruciforms and denatured loops, complicates the topological and geometric analysis of these molecules. In particular, the duplex axis is often difficult to define. In consequence, the usual conservation condition, Lk = Tw + Wr, is often ina...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(87)90337-8
更新日期:1987-05-05 00:00:00
abstract::During homologous recombination, genetic information is physically exchanged between parental DNAs via crossing single strands of the same polarity within a four-way DNA junction called a Holliday structure. This process is terminated by the endonucleolytic activity of resolvases, which convert the four-way DNA back t...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/s0022-2836(02)00594-6
更新日期:2002-08-02 00:00:00
abstract::Riboswitches are noncoding RNA elements that are commonly found in the 5'-untranslated region of bacterial mRNA. Binding of a small-molecule metabolite to the riboswitch aptamer domain guides the folding of the downstream sequence into one of two mutually exclusive secondary structures that directs gene expression. Th...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2008.10.074
更新日期:2009-01-23 00:00:00
abstract::Tafazzin is a mitochondrial enzyme that exchanges fatty acids between phospholipids by phospholipid-lysophospholipid transacylation. The reaction alters the molecular species composition and, as a result, the physical properties of lipids. In vivo, the most important substrate of tafazzin is the mitochondria-specific ...
journal_title:Journal of molecular biology
pub_type: 杂志文章,评审
doi:10.1016/j.jmb.2020.03.026
更新日期:2020-08-21 00:00:00
abstract::The crystal structure of human sex hormone-binding globulin (SHBG) has revealed how 5alpha-dihydrotestosterone intercalates between the two seven-stranded beta-sheets of its amino-terminal laminin G-like domain. However, a region of disorder (residues 130 to 135 of SHBG) was identified together with a zinc-binding sit...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/S0022-2836(02)00169-9
更新日期:2002-05-03 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::To investigate the relationships between sequence conservation, protein stability, and protein function, we have measured the thermodynamic stability, folding kinetics, and in vitro peptide-binding activity of a large number of single-site substitutions in the hydrophobic core of the Fyn SH3 domain. Comparison of thes...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2003.08.035
更新日期:2003-10-24 00:00:00
abstract::The 1.94 A resolution three-dimensional structure of oxidized horse heart cytochrome c has been elucidated and refined to a final R-factor of 0.17. This has allowed for a detailed assessment of the structural features of this protein, including the presence of secondary structure, hydrogen-bonding patterns and heme ge...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(90)90200-6
更新日期:1990-07-20 00:00:00
abstract::3-Methylitaconate-Delta-isomerase (Mii) participates in the nicotinate fermentation pathway of the anaerobic soil bacterium Eubacterium barkeri (order Clostridiales) by catalyzing the reversible conversion of (R)-3-methylitaconate (2-methylene-3-methylsuccinate) to 2,3-dimethylmaleate. The enzyme is also able to catal...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2009.06.052
更新日期:2009-08-21 00:00:00
abstract::The structure of the Escherichia coli gene coding for the metabolically stable 4.5 S RNA has been determined by cloning and DNA sequence analysis. Results from Southern hybridization assays carried out prior to cloning show the 4.5 S DNA to be limited to a single locus in the E. coli K12 genome. A 5.4 X 10(3) base DNA...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(84)90236-5
更新日期:1984-09-25 00:00:00
abstract::The structure of three consecutive laminin-type EGF-like (LE) modules of mouse laminin gammma1 chain, gamma1III3-5 (positions 738 to 899), has been determined by multiple isomorphous replacement in a crystal of space group p6(4)22 (a=b=74.57 angstroms, c = 185.11 angstroms and gamma = 120 degrees). The crystal structu...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1996.0191
更新日期:1996-04-05 00:00:00
abstract::In bacteriophages of the cystovirus family, the polymerase complex (PX) encodes a 75-kDa RNA-directed RNA polymerase (P2) that transcribes the double-stranded RNA genome. Also a constituent of the PX is the essential protein P7 that, in addition to accelerating PX assembly and facilitating genome packaging, plays a re...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2014.04.028
更新日期:2014-07-15 00:00:00
abstract::Filamentous bacteriophage M13 is a single-stranded DNA phage about 65 A in diameter and 9300 A long. X-ray diffraction studies of magnetically oriented fibers of native, mercury and iodine-labeled phage particles have been used to determine the arrangement of the major coat protein, the gene 8 product, in the virion. ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(92)90960-r
更新日期:1992-07-20 00:00:00
abstract::Biosynthesis of NAD(P) in bacteria occurs either de novo or through one of the salvage pathways that converge at the point where the reaction of nicotinate mononucleotide (NaMN) with ATP is coupled to the formation of nicotinate adenine dinucleotide (NaAD) and inorganic pyrophosphate. This reaction is catalyzed by nic...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2008.10.037
更新日期:2009-01-23 00:00:00
abstract::The use of carbohydrate-mimicking peptides to induce immune responses against surface polysaccharides of pathogenic bacteria offers a novel approach to vaccine development. Factors governing antigenic and immunogenic mimicry, however, are complex and poorly understood. We have addressed this question using the anti-li...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2009.03.057
更新日期:2009-05-15 00:00:00
abstract::The enantioselectivity of lipase from Burkhorderia cepacia KWI-56 has been inverted using a novel in vitro technique for construction and screening of a protein library by single-molecule DNA amplification by PCR followed by in vitro coupled transcription/translation system termed single-molecule-PCR-linked in vitro e...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/s0022-2836(03)00782-4
更新日期:2003-08-15 00:00:00
abstract::The FLP recombinase of the 2 mu plasmid of Saccharomyces cerevisiae binds to a target containing three 13 base-pair symmetry elements called a, b and c. The symmetry elements b and c are in direct orientation while the a element is in inverted orientation with respect to b and c on the opposite side of an eight base-p...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/s0022-2836(05)80320-1
更新日期:1990-11-20 00:00:00
abstract::Catalytic and other functionally important residues in proteins can often be mutated to yield more stable proteins. Many of these residues are charged residues that are located in electrostatically unfavorable environments. Here it is demonstrated that because continuum electrostatics methods can identify these destab...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.2001.5009
更新日期:2001-09-28 00:00:00
abstract::Nuclear protein-coding genes of euglenids (Discoba, Euglenozoa, Euglenida) contain conventional (spliceosomal) and nonconventional introns. The latter have been found only in euglenozoans. A unique feature of nonconventional introns is the ability to form a stable and slightly conserved RNA secondary structure bringin...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2020.166758
更新日期:2021-02-05 00:00:00
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journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1995.0395
更新日期:1995-07-21 00:00:00
abstract::The G.U wobble base-pair in the acceptor helix of Escherichia coli tRNAAlais critical for aminoacylation by the alanine synthetase. Previous work by several groups probed the mechanism of enzyme recognition of G.U by a structure-function analysis of mutant tRNAs using either a cell assay (amber suppressor tRNA) or a t...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.2884
更新日期:1999-07-09 00:00:00
abstract::A survey of known protein structures reveals that approximately 70% of serine residues and at least 85% (potentially 100%) of threonine residues in helices make hydrogen bonds to carbonyl oxygen atoms in the preceding turn of the helix. The high frequency of intrahelical hydrogen bonding is of particular significance ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(84)90446-7
更新日期:1984-05-05 00:00:00
abstract::The SgrAI endonuclease displays its maximal activity on DNA with two copies of its recognition sequence, cleaving both sites concertedly. While most restriction enzymes that act concurrently at two sites are tetramers, SgrAI is a dimer in solution. Its reaction at two cognate sites involves the association of two DNA-...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2005.04.053
更新日期:2005-07-08 00:00:00
abstract::Binary complexes between messenger RNA and E. coli ribosomes were examined. A ribosome-mRNA binary complex on T4 gene 32 mRNA withstood inhibition by antibodies against ribosomal protein S1. Anti-S1 blocks ternary complex formation, as measured by "extension inhibition" or "toeprinting" analysis, only when preincubate...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(91)90876-8
更新日期:1991-03-05 00:00:00
abstract::Ras GTPase mediates several cellular signal transduction pathways and is found mutated in a large number of cancers. It is active in the GTP-bound state, where it interacts with effector proteins, and at rest in the GDP-bound state. The catalytic domain is tethered to the membrane, with which it interacts in a nucleot...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2013.10.036
更新日期:2014-02-06 00:00:00
abstract::The growth of one group of amber mutants of R17 (class A) in non-permissive hosts results in a burst of bacteriophage-like particles, which are defective in that they are non-infectious. Here studies of particles produced by the growth of wild-type R17 and four class A mutants on AB301, a non-permissive Hfr Escherichi...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(66)90016-7
更新日期:1966-11-28 00:00:00
abstract::The exon junction complex (EJC) is a macromolecular complex deposited at splice junctions on mRNAs as a consequence of splicing. At the core of the EJC are four proteins: eIF4AIII, a member of the DExH/D-box family of NTP-dependent RNA binding proteins, Y14, Magoh, and MLN51. These proteins form a stable heterotetrame...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2006.05.049
更新日期:2006-07-21 00:00:00
abstract::The positive transcription elongation factor b (P-TEFb), composed of cyclin-dependent kinase 9 and cyclin T1, stimulates the elongation of transcription by hyperphosphorylating the C-terminal region of RNA polymerase II. Aberrant activation of P-TEFb results in manifestations of cardiac hypertrophy in mice, suggesting...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2008.07.017
更新日期:2008-10-03 00:00:00
abstract::The temperature induced unfolding/dissociation of the dimeric subtilisin inhibitor from Streptomyces and its mutant D83C having an S-S crosslink between the subunits has been studied calorimetrically. Comparison of the entropies measured at different concentrations of dimer showed that the entropy cost of crosslinking...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1997.1368
更新日期:1997-11-14 00:00:00