Abstract：
:Two mechanisms have thus far been characterized for the assistance by chaperonins of the folding of other proteins. The first and best described is that of the prokaryotic chaperonin GroEL, which interacts with a large spectrum of proteins. GroEL uses a nonspecific mechanism by which any conformation of practically any unfolded polypeptide interacts with it through exposed, hydrophobic residues. ATP binding liberates the substrate in the GroEL cavity where it is given a chance to fold. A second mechanism has been described for the eukaryotic chaperonin CCT, which interacts mainly with the cytoskeletal proteins actin and tubulin. Cryoelectron microscopy and biochemical studies have revealed that both of these proteins interact with CCT in quasi-native, defined conformations. Here we have performed a detailed study of the docking of the actin and tubulin molecules extracted from their corresponding CCT:substrate complexes obtained from cryoelectron microscopy and image processing to localize certain regions in actin and tubulin that are involved in the interaction with CCT. These regions of actin and tubulin, which are not present in their prokaryotic counterparts FtsA and FtsZ, are involved in the polymerization of the two cytoskeletal proteins. These findings suggest coevolution of CCT with actin and tubulin in order to counteract the folding problems associated with the generation in these two cytoskeletal protein families of new domains involved in their polymerization.
journal_name
J Struct Bioljournal_title
Journal of structural biologyauthors
Llorca O,Martín-Benito J,Gómez-Puertas P,Ritco-Vonsovici M,Willison KR,Carrascosa JL,Valpuesta JMdoi
10.1006/jsbi.2001.4359keywords:
subject
Has Abstractpub_date
2001-08-01 00:00:00pages
205-18issue
2eissn
1047-8477issn
1095-8657pii
S104784770194359Xjournal_volume
135pub_type
杂志文章abstract：:Sickle hemoglobin (HbS) polymerization initiates in the deoxy state with the binding of hydrophobic patch formed by the isopropyl group of βVal6 residue of a hemoglobin tetramer with the hydrophobic pocket of another tetramer, whose hydrophobic patch binds to the hydrophobic groove of a third molecule. Subsequent elon...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2017.04.009
更新日期：2017-07-01 00:00:00
abstract：:In COPII mediated vesicle formation, Sec13/Sec31 heterotetramers play a role in organizing the membranes into a spherical vesicle. There they oligomerize into a cage that interacts with the other COPII proteins to direct vesicle formation and concentrate cargo into a bud. In this role they must be flexible to accommod...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2018.08.016
更新日期：2018-11-01 00:00:00
abstract：:The actin-like protein ParM forms the cytomotive filament of the ParMRC system, a type II plasmid segregation system encoded by Escherichia coli R1 plasmid. We report an 8.5Å resolution reconstruction of the ParM filament, obtained using cryo-electron microscopy. Fitting of the 3D density reconstruction with monomeric...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2013.02.010
更新日期：2013-10-01 00:00:00
abstract：:The photosynthetic membrane in purple bacteria contains several pigment-protein complexes that assure light capture and establishment of the chemiosmotic gradient. The bioenergetic tasks of the photosynthetic membrane require the strong interaction between these various complexes. In the present work, we acquired the ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2010.08.010
更新日期：2011-01-01 00:00:00
abstract：:Lysozymes from family 22 of glycoside hydrolases are usually part of the defense system against bacteria. However in ruminant artiodactyls and saprophagous insects, lysozymes are involved in the digestion of bacteria. Here, we report the first crystallographic structure of a digestive lysozyme in its native and comple...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2007.07.008
更新日期：2007-10-01 00:00:00
abstract：:We describe novel structural domains in in vitro reconstituted Xenopus sperm nuclei, which we term RPA bodies; RPA is the only known marker of these structures. These bodies contain DNA and represent special chromatin domains as seen by transmission electron microscopy. We show that RPA bodies exhibit a similar ultras...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.2000.4229
更新日期：2000-04-01 00:00:00
abstract：:HIV-1 Rev mediates the nuclear export of unspliced and partially-spliced viral transcripts for the production of progeny genomes and structural proteins. In this process, four (or more) copies of Rev assemble onto a highly-structured 351-nt region in such viral transcripts, the Rev response element (RRE). How this occ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2018.03.011
更新日期：2018-08-01 00:00:00
abstract：:The skeletons of demosponges, such as Ianthella basta, are known to be a composite material containing organic constituents. Here, we show that a filigree chitin-based scaffold is an integral component of the I. basta skeleton. These chitin-based scaffolds can be isolated from the sponge skeletons using an isolation a...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2009.06.018
更新日期：2009-12-01 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：:Molecular genetic studies with prokaryotic microorganisms reveal that many different molecular processes contribute to the formation of spontaneous mutations. Besides infidelities in DNA replication and the consequences of environmental mutagens, enzyme-mediated DNA rearrangements bring about important, evolutionarily...
journal_title：Journal of structural biology
pub_type： 杂志文章,评审
doi：10.1016/1047-8477(90)90064-j
更新日期：1990-07-01 00:00:00
abstract：:The biomechanical properties of the zone of calcified cartilage (ZCC) in articulating joints are of clinical relevance due to the role ZCC plays in load transfer from cartilage to bone. To determine the micron-level mechanical properties and their correlation to mineral concentration in the ZCC, we combined nanoindent...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2004.10.010
更新日期：2005-02-01 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：:Tomo3D is a program for fast tomographic reconstruction on multicore computers. Its high speed stems from code optimization, vectorization with Streaming SIMD Extensions (SSE), multithreading and optimization of disk access. Recently, Advanced Vector eXtensions (AVX) have been introduced in the x86 processor architect...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2014.11.009
更新日期：2015-02-01 00:00:00
abstract：:Formation of filaments by the Ure2 protein constitutes the molecular mechanism of the [URE3] prion in yeast. According to the "amyloid backbone" model, the N-terminal asparagine-rich domains of Ure2p polymerize to form an amyloid core fibril that is surrounded by C-terminal domains in their native conformation. Protea...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2005.02.007
更新日期：2005-05-01 00:00:00
abstract：:Tobacco streak virus (TSV), the type member of Ilarvirus genus, is a major plant pathogen. TSV purified from infected plants consists of a ss-RNA genome encapsidated in spheroidal particles with diameters of 27, 30 and 33nm constructed from multiple copies of a single species of coat protein (CP) subunits. Apart from ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2015.12.007
更新日期：2016-02-01 00:00:00
abstract：:Seeding has been critical for obtaining diffraction-quality crystals for many structures. In this article, applications and recommendations for seeding are presented based on examples from our laboratory and other groups. The implementation of seeding in high-throughput crystallization, robotics, and other emerging te...
journal_title：Journal of structural biology
pub_type： 杂志文章,评审
doi：10.1016/s1047-8477(03)00039-x
更新日期：2003-04-01 00:00:00
abstract：:We present a sample preparation method for cryo-electron microscopy (cryo-EM) that requires only 3-20nL of sample to prepare a cryo-EM grid, depending on the protocol used. The sample is applied and spread on the grid by a microcapillary. The procedure does not involve any blotting steps, and real-time monitoring allo...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2016.11.002
更新日期：2017-03-01 00:00:00
abstract：:The repetitive Gly-X-Y sequence is the telltale sign of triple helical domains in collagens and collagen-like proteins. Most collagen sequences contain sporadic interruptions of this pattern, which may have functional roles in molecular flexibility, assembly or molecular recognition. However, the structural signatures...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2014.03.022
更新日期：2014-06-01 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：:By direct immunolabeling we have mapped the distribution of photosystem II (PS II) and cytochrome b6/f on the surfaces of photosynthetic membranes isolated from spinach. Photosynthetic membranes were attached to a support and gently disrupted to expose the occluded outer stacked surface, prior to labeling. Polyclonal ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1993.1029
更新日期：1993-07-01 00:00:00
abstract：:Cryo-electron microscopy (cryo-EM) of frozen-hydrated preparations of isolated macromolecular complexes is the method of choice to obtain the structure of complexes that cannot be easily studied by other experimental methods due to their flexibility or large size. An increasing number of macromolecular structures are ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2016.04.007
更新日期：2016-06-01 00:00:00
abstract：:AAA+ proteins remodel target substrates in an ATP-dependent manner, an activity that is of central importance for a plethora of cellular processes. While sharing a similar hexameric structure AAA+ proteins must exhibit differences in substrate recognition to fulfil their diverse biological functions. Here we describe ...
journal_title：Journal of structural biology
pub_type： 杂志文章,评审
doi：10.1016/j.jsb.2003.10.009
更新日期：2004-04-01 00:00:00
abstract：:The first step to understanding brain function is to determine the brain's network structure. We report a three-dimensional analysis of the brain network of the fruit fly Drosophila melanogaster by synchrotron-radiation tomographic microscopy. A skeletonized wire model of the left half of the brain network was built b...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2013.08.012
更新日期：2013-11-01 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：:The unsupervised segmentation method proposed in the current study follows the evolutional ability of human vision to extrapolate significant structures in an image. In this work we adopt the perceptual grouping strategy by selecting the spectral clustering framework, which is known to capture perceptual organization ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2013.10.013
更新日期：2013-12-01 00:00:00
abstract：:In fishes, like in amphibians, it is well established that variations in rRNA activity occur during oogenesis. Contrary to amphibians, however, little is known about the ultrastructural changes of the nucleolus during fish oogenesis. Evolution of the nucleolus has been followed during oogenesis in the teleost fish Bar...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2005.07.006
更新日期：2005-10-01 00:00:00
abstract：:Nacre has long served as a model for understanding the biomineralization mechanism and designing bio-inspired materials. However, its basic building blocks, the aragonite tablets, are still under debate in terms of their fine structure at the nanoscale and corresponding formation mechanism. Here, using a field emissio...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2013.01.010
更新日期：2013-04-01 00:00:00
abstract：:We consider the problem of estimating an unbiased and reference-free ab initio model for non-symmetric molecules from images generated by single-particle cryo-electron microscopy. The proposed algorithm finds the globally optimal assignment of orientations that simultaneously respects all common lines between all imag...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2017.09.007
更新日期：2017-11-01 00:00:00
abstract：:Commonly employed data models for maximum likelihood refinement of electron microscopy images behave poorly in the presence of normalization errors. Small variations in background mean or signal brightness are relatively common in cryo-electron microscopy data, and varying signal-to-noise ratios or artifacts in the im...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2009.02.007
更新日期：2009-05-01 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
