Abstract:
:The innermost chorionic layer (ICL) within egg shells of Drosophila melanogaster is composed of thin, abutting three-dimensional crystalline plates which form a closed, membrane-like sheath. Collectively, the crystals within the sheath appear to form a family of related three-dimensional crystals in space group C222; however, specimens prepared for electron microscopy are actually two-dimensional crystals in c222. The projected structures of the negatively stained crystals have been studied by minimal dose electron microscopy employing image reconstruction methods. Thin sections indicate that unit cells within the ICL are composed of paired layers; top and bottom layers are related by centrally located 2-fold axes, aligned parallel to the surface of the ICL. The most probable structural unit of the crystals is a tetramer of chorin dimers with a point group symmetry of 222, which is denoted a chorin octamer. Projection maps were computed from average transforms of two-dimensional crystals for delta (the primitive unit cell angle) equal to 84 degrees, 90 degrees and 97 degrees (+/- 1.5 degrees). The maps indicate that the molecular transitions responsible for the observed family of crystals involve concerted intramolecular rearrangements about molecular 2-fold axes. The significance in vivo of the family of crystals within the ICL is not known; however, structural considerations suggest that the observed polymorphism may reflect one facet of an intrinsic bonding flexibility of the ICL octamer that may play a role in the formation of interplate junctions and the assembly of a continuous closed sheath. The ICL may therefore serve as a structural bridge between the vitelline membrane-wax layer and the endochondrial floor, allowing the larva to shed the inner egg shell layers during hatching.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Akey CW,Edelstein SJdoi
10.1016/0022-2836(87)90350-0subject
Has Abstractpub_date
1987-02-20 00:00:00pages
673-83issue
4eissn
0022-2836issn
1089-8638pii
0022-2836(87)90350-0journal_volume
193pub_type
杂志文章abstract::We use flexible backbone protein design to explore the sequence and structure neighborhoods of naturally occurring proteins. The method samples sequence and structure space in the vicinity of a known sequence and structure by alternately optimizing the sequence for a fixed protein backbone using rotamer based sequence...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.11.062
更新日期:2005-02-18 00:00:00
abstract::The crystal structures of glycosylated native proteinase A, an aspartic proteinase found in the vacuole of Saccharomyces cerevisiae, and its complex with a difluorostatone-containing tripeptide have been determined by molecular replacement to 3.5 A and 2.4 A resolutions, respectively. Superposition of the bound and na...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1996.0880
更新日期:1997-04-11 00:00:00
abstract::TWINKLE is the helicase at the mitochondrial DNA (mtDNA) replication fork in mammalian cells. Mutations in the PEO1 gene, which encodes TWINKLE, cause autosomal dominant progressive external ophthalmoplegia (AdPEO), a disorder associated with deletions in mtDNA. Here, we characterized seven different AdPEO-causing mut...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2008.01.035
更新日期:2008-03-28 00:00:00
abstract::In bacteria, protein overproduction results in the formation of inclusion bodies, sized protein aggregates showing amyloid-like properties such as seeding-driven formation, amyloid-tropic dye binding, intermolecular beta-sheet architecture and cytotoxicity on mammalian cells. During protein deposition, exposed hydroph...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2007.09.004
更新日期:2007-11-16 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::Solvent binding in the nucleosome core particle containing a 147 base pair, defined-sequence DNA is characterized from the X-ray crystal structure at 1.9 A resolution. A single-base-pair increase in DNA length over that used previously results in substantially improved clarity of the electron density and accuracy for ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/S0022-2836(02)00386-8
更新日期:2002-06-21 00:00:00
abstract::gamma-Glutamyltranspeptidase (EC 2.3.2.2) from Escherichia coli K-12 has been purified and crystallized by means of vapor diffusion in hanging drops. Two kinds of crystals on cell dimensions were found for X-ray diffraction analysis, one from ammonium sulfate and the other from polyethylene glycol 6000 as precipitants...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1993.1677
更新日期:1993-12-20 00:00:00
abstract::Bacteriophages are involved in many aspects of the spread and establishment of virulence factors in Staphylococcus aureus, including the mobilization of genetic elements known as S. aureus pathogenicity islands (SaPIs), which carry genes for superantigen toxins and other virulence factors. SaPIs are packaged into phag...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2010.11.047
更新日期:2011-01-21 00:00:00
abstract::The three-dimensional structures of double and single-shelled simian rotavirus have been determined to a resolution of 40 A by image processing electron micrographs of unstained, unfixed virus particles embedded in vitreous ice. This study demonstrates that the icosahedral surface lattices in these structures have a t...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(88)90313-0
更新日期:1988-01-20 00:00:00
abstract::The segment of the vaccinia DNA topoisomerase from residues 143 to 167 (VGLLTLKNKHIEISPDEIVIKFVGK) is conserved in other members of the eukaryotic type I topoisomerase family. In order to gauge the function of this region, we performed a mutational analysis in which 23 of 25 positions were substituted by alanine. Seve...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1996.0568
更新日期:1996-10-25 00:00:00
abstract::Detachment of flagella in Chlamydomonas reinhardii stimulates a rapid accumulation of tubulin mRNAs. The induced tubulin mRNAs are normally rapidly degraded following flagellar regeneration, but inhibition of protein synthesis with cycloheximide prevents their degradation. alpha-Tubulin poly(A) tail lengths were measu...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(89)90243-x
更新日期:1989-06-20 00:00:00
abstract::Along with the discovery of tumor-driven inflammatory pathways, there has been a considerable progress over the past 10years in understanding the mechanisms leading to cancer immunosurveillance and immunoediting. Several regulatory pathways, typically involved in immune cell homeostasis, are co-opted by cancer cells t...
journal_title:Journal of molecular biology
pub_type: 杂志文章,评审
doi:10.1016/j.jmb.2016.03.021
更新日期:2016-08-14 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::A total of 76 independent spontaneous mutants in the hprt gene of V79 Chinese hamster cells have been analyzed. These mutants were obtained in two different laboratories, 17 and 59 mutants in sets 1 and 2, respectively, under different cell culture conditions. Mutation analysis was performed by amplification of hprt c...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(92)90979-t
更新日期:1992-02-05 00:00:00
abstract::Two crystal forms (P6(3) and R3) of human annexin V have been crystallographically refined at 2.3 A and 2.0 A resolution to R-values of 0.184 and 0.174, respectively, applying very tight stereochemical restraints with deviations from ideal geometry of 0.01 A and 2 degrees. The three independent molecules (2 in P6(3), ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(92)90984-r
更新日期:1992-02-05 00:00:00
abstract::Annexins constitute a family of phospholipid- and Ca(2+)-binding proteins involved in a variety of membrane-related processes. The property of several annexins, including annexin A5, to self-organize at the surface of lipid membranes into 2D ordered arrays has been proposed to be functionally relevant in cellular cont...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.2000.4183
更新日期:2000-12-08 00:00:00
abstract::Pathogenic strains of Helicobacter pylori use a type IV secretion system (T4SS) to deliver the toxin CagA into human host cells. The T4SS, along with the toxin itself, is coded into a genomic insert, which is termed the cag pathogenicity island. The cag pathogenicity island contains about 30 open-reading frames, for m...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2008.12.018
更新日期:2009-02-13 00:00:00
abstract::The combined biochemical and structural study of hundreds of protein-DNA complexes has indicated that sequence-specific interactions are mediated by two mechanisms termed direct and indirect readout. Direct readout involves direct interactions between the protein and base-specific atoms exposed in the major and minor ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2003.10.071
更新日期:2004-01-09 00:00:00
abstract::The crystal structure of a construct consisting of the FERM and SH2-like domains of the human Janus kinase 1 (JAK1) bound to a fragment of the intracellular domain of the interferon-λ receptor 1 (IFNLR1) has been determined at the nominal resolution of 2.1Å. In this structure, the receptor peptide forms an 85-Å-long e...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2016.10.005
更新日期:2016-11-20 00:00:00
abstract::The Alu Ya-lineage is a group of related, short interspersed elements (SINEs) found in primates. This lineage includes subfamilies Ya1-Ya5, Ya5a2 and others. Some of these subfamilies are still actively mobilizing in the human genome. We have analyzed 2482 elements that reside in the human genome draft sequence and fo...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.07.016
更新日期:2004-09-03 00:00:00
abstract::G protein coupled receptors (GPCRs) are integral membrane proteins that mediate cellular responses to a wide variety of extracellular signals. However, the structural basis for activation of this class of receptors by ligand binding is not well understood. We report here the use of a systematic genetic protocol for id...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1996.0816
更新日期:1997-02-28 00:00:00
abstract::Clinical studies have revealed that mutations in the ventricular myosin regulatory light chain (RLC) lead to the development of familial hypertrophic cardiomyopathy (FHC), an autosomal dominant disease characterized by left ventricular hypertrophy, myofibrillar disarray and sudden cardiac death. While mutations in oth...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2006.06.018
更新日期:2006-08-11 00:00:00
abstract::We describe experiments that enable us to track the presence and direction of the DNA bend induced by Escherichia coli catabolite activator protein (CAP) through the intermediate stages of transcription initiation at the lac promoter. Transcriptional complexes examined were formed on superhelical templates to enhance ...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/0022-2836(91)90562-k
更新日期:1991-05-20 00:00:00
abstract::The interaction of archaeal family B DNA polymerases with deaminated bases has been examined. As determined previously by our group, the polymerase binds tightly to uracil (the deamination product of cytosine), in single-stranded DNA, and stalls replication on encountering this base. DNA polymerisation was also inhibi...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2007.07.015
更新日期:2007-09-28 00:00:00
abstract::Structural properties and folding of interleukin-1 receptor antagonist (IL-1ra), a therapeutically important cytokine with a symmetric beta-trefoil topology, are characterized using optical spectroscopy, high-resolution NMR, and size-exclusion chromatography. Spectral contributions of two tryptophan residues, Trp17 an...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2007.02.031
更新日期:2007-05-11 00:00:00
abstract::Although chemical signaling during embryogenesis is readily addressed by a plethora of available techniques, the developmental functions of ionic signaling are still poorly understood. It is increasingly realized that bioelectric events in nonneural cells are critical for pattern regulation, but their study has been h...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2019.10.029
更新日期:2020-01-17 00:00:00
abstract::The solution structure of growth factor receptor-bound protein 2 (Grb2) SH2 complexed with a Shc-derived phosphotyrosine (pTyr)-containing peptide was determined by nuclear magnetic resonance (NMR) spectroscopy. The pTyr binding site of Grb2 SH2 was similar to those of other SH2 domains. In contrast, the amino acid re...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1999.2792
更新日期:1999-06-11 00:00:00
abstract::Retinoic-acid mediated differentiation of F9 cells is accompanied by an increased transcription of the histone H1zero gene. This increase is an early response after addition of retinoic acid, suggesting a direct effect of the hormone on transcription of the gene. We show now that the promoter of histone H1zero contain...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1006/jmbi.1994.1555
更新日期:1994-09-09 00:00:00
abstract::We report a detailed all-atom simulation of the folding of the GCAA RNA tetraloop. The GCAA tetraloop motif is a very common and thermodynamically stable secondary structure in natural RNAs. We use our simulation methods to study the folding behavior of a 12-base GCAA tetraloop structure with a four-base helix adjacen...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2004.09.041
更新日期:2004-11-12 00:00:00
abstract::The aggregation of alpha-synuclein is believed to be a critical step in the etiology of Parkinson's disease. A variety of biophysical techniques were used to investigate the aggregation and fibrillation of alpha-synuclein in which one of the four intrinsic Tyr residues was replaced by Trp, and two others by Phe, in or...
journal_title:Journal of molecular biology
pub_type: 杂志文章
doi:10.1016/j.jmb.2005.08.046
更新日期:2005-10-21 00:00:00