Abstract：
:Nucleoids isolated from Escherichia coli at low salt concentrations in the presence of spermidine (Kornberg et al., Proc. Natl. Acad. Sci. USA, 71, 3189-3193 (1974)) retain large amounts of protein and RNA and are, thus, potentially useful in structural and other studies. However, these preparations have neither been visualized nor extensively characterized with regard to their protein and other components. We have investigated this type of nucleoid preparation and here supply both light and electron microscope appearances and a description of the DNA-associated proteins. Light microscopy is used to follow the stages of nucleoid release and to demonstrate characteristically rounded nucleoids after chloramphenicol treatment of the cells from which the nucleoids were isolated. The nucleoids are "envelope-associated" particles. Electron microscopy shows an irregular central core that is partially covered with small, membranous vesicles. A significant fraction of the nucleoids have a characteristic doublet/dumbbell-shaped appearance by light microscopy. The nucleoids contain large amounts of protein and RNA in addition to DNA. The DNA and RNA are rendered acid-soluble by very low levels of nucleases, indicating an open structure. A small group of proteins, including H-NS, FIS, HU, and RNA polymerase, is released from the particles upon enzymatic digestion of the DNA.
journal_name
J Struct Bioljournal_title
Journal of structural biologyauthors
Murphy LD,Zimmerman SBdoi
10.1006/jsbi.1997.3883subject
Has Abstractpub_date
1997-08-01 00:00:00pages
321-35issue
3eissn
1047-8477issn
1095-8657pii
S1047-8477(97)93883-1journal_volume
119pub_type
杂志文章abstract：:Human scalp hairs are often examined microscopically to study the variation and diversity among a range of visible morphological traits. In this study, we focused on the ultrastructure of human scalp hair within its keratinized matrix, emphasizing, the density and distribution of melanosomes, variation in cuticle thic...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2018.11.008
更新日期：2019-01-01 00:00:00
abstract：:A characteristic feature of the dense phases formed by fiber-shaped molecules is their organization into parallel rods packed in a hexagonal or pseudo-hexagonal lateral network. This is typically the case for the collagen triple helices inside fibrils, as confirmed by recent X-ray diffraction experiments carried out o...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2010.11.018
更新日期：2011-02-01 00:00:00
abstract：:The structure of Panicum Mosaic Virus (PMV) was determined by X-ray diffraction analysis to 2.9Å resolution. The crystals were of pseudo symmetry F23; the true crystallographic unit cell was of space group P2(1) with a=411.7Å, b=403.9Å and c=412.5Å, with β=89.7°. The asymmetric unit was two entire T=3 virus particles,...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2012.10.012
更新日期：2013-01-01 00:00:00
abstract：:Riboflavin synthase is a trimer of identical 23-kDa subunits. The primary structure is characterized by considerable similarity of the C-terminal and N-terminal parts. Recombinant riboflavin synthase of Escherichia coli and Bacillus subtilis was crystallized by the vapor diffusion method. Crystals of E. coli riboflavi...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1997.3935
更新日期：1998-01-01 00:00:00
abstract：:The acetyl-CoA decarbonylase/synthase (ACDS) complex is responsible for synthesis and cleavage of acetyl-CoA in methanogens. The complex is composed of five different subunits, with a probable stoichiometry of alpha(8)beta(8)gamma(8)delta(8)epsilon(8). The native molecular mass of a subcomponent of the ACDS complex fr...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1999.4163
更新日期：1999-12-15 00:00:00
abstract：:Substrate binding to enzymes often follows a precise order where catalysis is accomplished through programmed conformational changes. Short-chain dehydrogenase/reductase (SDR) enzymes follow sequential order 'bi-bi' reaction kinetics. The mechanistic study of a SDR homolog, reductase (R) domain, from multifunctional e...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2014.07.008
更新日期：2014-09-01 00:00:00
abstract：:We have developed a new two-step algorithm to determine the astigmatism of images from transmission electron microscopes (TEMs). Instead of computing the radial average of the power spectrum, we divide the power spectrum of a TEM image 1 to m (typically 32) sectors. We use a technique based on perturbation analysis of...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2006.07.021
更新日期：2007-01-01 00:00:00
abstract：:We have shown by in vitro development of staged follicles in the presence of tritiated proline, as well as by immunoblot analysis, that the Dvs19 and DVS15 chorion proteins of Drosophila virilis are synthesized by the follicular epithelium and are incorporated in the chorion at the terminal stages of choriogenesis. Li...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1998.4999
更新日期：1998-10-01 00:00:00
abstract：:Ion mobility mass spectrometry was employed to study the structure of the βB2B3-crystallin heterodimer following oxidation through its increased exposure to hydroxyl radicals. The results demonstrate that the heterodimer can withstand limited oxidation through the incorporation of up to some 10 oxygen atoms per subuni...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2014.11.006
更新日期：2015-01-01 00:00:00
abstract：:While cryo-electron tomography (cryo-ET) can reveal biological structures in their native state within the cellular environment, it requires the production of high-quality frozen-hydrated sections that are thinner than 300nm. Sample requirements are even more stringent for the visualization of membrane-bound protein c...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2016.07.010
更新日期：2017-02-01 00:00:00
abstract：:We have studied two members of the family of morphogenetic factors or chaperonins, the GroEL-like factors from Escherichia coli and Bacillus subtilis, in order to determine the possible structural basis of their related function in promoting the correct and efficient assembly of biological oligomers. The main objectiv...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/1047-8477(91)90071-4
更新日期：1991-06-01 00:00:00
abstract：:In cryo-electron microscopy (cryo-EM) single-particle reconstruction, the heterogeneity of two-dimensional projection image data resulting from the co-existence of different conformational or ligand binding states of a macromolecular complex remains a major obstacle as it impairs the validity of reconstructed density ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2006.06.012
更新日期：2007-01-01 00:00:00
abstract：:DciA is a newly discovered bacterial protein involved in loading the replicative helicase DnaB onto DNA at the initiation step of chromosome replication. Its three-dimensional structure is composed of a folded N-terminal domain (residues 1-111) resembling K Homology domains and a long disordered C-terminal tail (resid...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2020.107573
更新日期：2020-10-01 00:00:00
abstract：:In the cornea, the precise organisation of fibrillar collagen and associated proteoglycans comprising the stromal extracellular matrix plays a major role in governing tissue form and function. Recently, abnormal collagen alignment was noted in the misshapen corneas of mature chickens affected by the retinopathy, globe...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2009.01.009
更新日期：2009-05-01 00:00:00
abstract：:The ability to convert into amyloid fibrils is a common feature of prion proteins. However, not all amyloid-forming proteins act as prions. Here, we compared two homologs of the yeast prion protein Ure2 from Saccharomyces cerevisiae and Saccharomyces paradoxus, ScUre2p and SpUre2p, which have different prion propensit...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2011.03.008
更新日期：2011-06-01 00:00:00
abstract：:The transcriptional regulator CpxR mediates an adaptive response to envelope stress, tightly linked to virulence and antibiotics resistance in several Gammaproteobacteria pathogens. In this work, we integrated crystallographic and small-angle X-ray scattering data to gain insights into the structure and conformational...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2018.08.001
更新日期：2018-11-01 00:00:00
abstract：:An approach to automated acquisition of cryoEM image data from lacey carbon grids using the Leginon program is described. Automated liquid nitrogen top up of the specimen holder dewar was used as a step towards full automation, without operator intervention during the course of data collection. During cryoEM studies o...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2010.08.014
更新日期：2010-12-01 00:00:00
abstract：:The lipopolysaccharide (LPS) of the Salmonella cell surface serves as the receptor for a very large number of bacterial viruses. The tailspike protein from these viruses recognizes the LPS as its initial receptor. It is proposed that the study of the P22 and epsilon 34 tailspike proteins could serve as a model for the...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1995.1053
更新日期：1995-11-01 00:00:00
abstract：:The yeast Saccharomyces cerevisiae mitochondrial matrix factor Mmf1, a member in the YER057c/Yigf/Uk114 family, participates in isoleucine biosynthesis and mitochondria maintenance. Mmf1 physically interacts with another mitochondrial matrix protein Mam33, which is involved in the sorting of cytochrome b₂ to the inter...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2011.05.005
更新日期：2011-09-01 00:00:00
abstract：:The carboxy-terminal region of the KCNH family of potassium channels contains a cyclic-nucleotide binding homology domain (CNBHD) that is important for channel gating and trafficking. The solution structure of the CNBHD of the KCNH potassium of zebrafish was determined using solution NMR spectroscopy. This domain exis...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2014.03.008
更新日期：2014-04-01 00:00:00
abstract：:Brain deposition of Aβ in the form of amyloid plaques is a pathological hallmark of Alzheimer's disease. There are two major species of Aβ in the brain: Aβ42 and Aβ40. Although Aβ40 is several-fold more abundant than Aβ42 in soluble form, Aβ42 is the major component of amyloid plaques. Structural knowledge of Aβ42 fib...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2016.01.013
更新日期：2016-04-01 00:00:00
abstract：:Light microscopy (LM) approaches are commonly used to attain a description of the cell structure. Even though LM, if compared to electron microscopy (EM), represents a very fast approach, its resolution is, in principle, much lower than in the case of EM. To improve the LM resolution, computational methods based on re...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/s1047-8477(02)00574-9
更新日期：2002-10-01 00:00:00
abstract：:The molecular mechanism underlining the antibacterial activity of the bacteriocin AS-48 is not known, and two different and opposite alternatives have been proposed. Available data suggested that the interaction of positively charged amino acids of AS-48 with the membrane would produce membrane destabilization and dis...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2015.03.006
更新日期：2015-05-01 00:00:00
abstract：:We describe here a set of multiresolution visualization and docking procedures that we refer to as the Situs package. The package was developed to provide an efficient and robust method for the fitting of atomic structures into low-resolution data. The current release was optimized specifically for the visualization a...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.2000.4350
更新日期：2001-02-01 00:00:00
abstract：:The bacterial injectisome and flagella both rely on type III secretion systems for their assembly. The syringe-like injectisome creates a continuous channel between the bacterium and the host cell, through which signal-modulating effector proteins are secreted. The inner membrane pore protein SctV controls the hierarc...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2020.107660
更新日期：2020-12-01 00:00:00
abstract：:F-plasmid-mediated bacterial conjugation was studied with hfr (traDts) and tra I mutant Escherichia coli donor strains. This allowed us to observe a statistically significant number of conjugation-specific contacts by video and electron microscopy. Single mating events between E. coli were observed in real time by vid...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/1047-8477(91)90018-r
更新日期：1991-10-01 00:00:00
abstract：:Long-depth imaging of specific gene expression in the midgestation whole-mount mouse embryo (WME) is demonstrated with single-photon excitation (1PE) confocal fluorescence microscopy and fluorescence in situ hybridization. Expression domains of Pax-6 mRNA transcripts were labeled with an in situ hybridization probe th...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.2000.4238
更新日期：2000-07-01 00:00:00
abstract：:It has been known since the 19th century that coral skeletons are built of aragonite crystals with taxonomy-linked arrangements, but the way by which each coral species controls this crystallization process remains an unsolved question. The problem became still more intriguing when it was shown that isotopic compositi...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2005.03.004
更新日期：2005-06-01 00:00:00
abstract：:A topological localization of epitopes on the surface of the Aa6 subunit of Androctonus australis hemocyanin has been carried out. First, immunocomplex strings composed of native hemocyanin and monoclonal antibodies were examined in the electron microscope and submitted to an image processing by correspondence analysi...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/1047-8477(90)90087-s
更新日期：1990-03-01 00:00:00
abstract：:A new method for the flexible fitting of high-resolution structures into low-resolution maps of macromolecular complexes from electron microscopy has been recently described in applications to simulated electron density maps. This method uses a linear combination of low-frequency normal modes in an iterative manner to...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2004.03.002
更新日期：2004-09-01 00:00:00
