Abstract：
:Four-helical bundles are the most abundant topological motif among helical folds. Their constituent helices show crossing angles that mainly cluster around +20 degrees (aligned) or -50 degrees (orthogonal). Bundles with all helices aligned are called 'square' and comprise four-helical coiled coils as their structurally most regular form. Since coiled coils can be described fully by parametric equations, they can serve as a reference point for quantifying the conformational space of all square bundles. To this end we have developed a program, samCC, which measures the deviation of a given bundle from an idealized coiled coil and decomposes this into axial rotation and axial, radial, and angular shifts. We present examples of analyses performed with the program and focus in particular on the axial rotation states of helices in coiled coils, in order to gain further insight into a proposed mechanism for transmembrane signal transduction, which involves a 26 degrees axial rotation of helices between a canonical coiled coil and a variant called the Alacoil. We find that, unlike expected from the mechanistic model, coiled coils show a continuum of axial rotation states, suggesting that the Alacoil does not represent a single, defined state. We also find that one of the originally proposed Alacoil proteins, Rop, in fact has canonical packing. SamCC is freely available as a web service athttp://toolkit.tuebingen.mpg.de/samcc.
journal_name
J Struct Bioljournal_title
Journal of structural biologyauthors
Dunin-Horkawicz S,Lupas ANdoi
10.1016/j.jsb.2010.01.023subject
Has Abstractpub_date
2010-05-01 00:00:00pages
226-35issue
2eissn
1047-8477issn
1095-8657pii
S1047-8477(10)00035-3journal_volume
170pub_type
杂志文章abstract：:Immunoelectron microscopy of serial sections of leaf cells of wheat doubly infected by wheat streak mosaic virus and Agropyron mosaic virus or wheat spindle streak mosaic virus showed that structural proteins or virions associated only with homologous cylindrical inclusions (CI) or with self in aggregates. CI protein ...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1993.1021
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journal_title：Journal of structural biology
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journal_title：Journal of structural biology
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journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.2000.4258
更新日期：2000-06-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
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journal_title：Journal of structural biology
pub_type： 杂志文章
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更新日期：2010-01-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
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journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1998.4032
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journal_title：Journal of structural biology
pub_type： 杂志文章
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更新日期：2006-10-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
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更新日期：1998-01-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
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更新日期：2019-10-01 00:00:00
abstract：:Enameloid, the hyper-mineralized tissue covering shark teeth is a complex structure resulting from both ameloblast and odontoblast activity. The way these two types of cells interact to set up this tissue is not fully understood and results in the formation of subunits in the enameloid: the Single Crystallite Enameloi...
journal_title：Journal of structural biology
pub_type： 杂志文章
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更新日期：2020-11-19 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2013.05.023
更新日期：2013-07-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1995.1044
更新日期：1995-09-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1994.1004
更新日期：1994-01-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1006/jsbi.1995.1026
更新日期：1995-07-01 00:00:00
abstract：:The skeletal system of Demospongiae consists of siliceous spicules, which are composed of an axial channel containing an organic axial filament (AF) surrounded by a compact layer of hydrated amorphous silica. Here we report the ultrastructural investigations of the AF of siliceous spicules from two Demospongiae: Suber...
journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/j.jsb.2017.03.005
更新日期：2017-06-01 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
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journal_title：Journal of structural biology
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更新日期：1997-12-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
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更新日期：2010-12-01 00:00:00
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journal_title：Journal of structural biology
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更新日期：2018-04-01 00:00:00
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journal_title：Journal of structural biology
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更新日期：1994-07-01 00:00:00
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更新日期：2007-01-01 00:00:00
abstract：:The 32 kDa hydrophilic and acidic enamelin, the most stable cleavage fragment of the enamel specific glycoprotein, is believed to play vital roles in controlling crystal nucleation or growth during enamel biomineralization. Circular dichroism and Fourier transform infrared spectra demonstrate that the secondary struct...
journal_title：Journal of structural biology
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abstract：:Cryo-tomography in the electron microscope is unique in its ability to provide high-resolution, three-dimensional structural information about cells, organelles and macromolecules in a nearly native, frozen-hydrated state. However, the phase-contrast imaging method used in conventional cryo-electron tomography fails t...
journal_title：Journal of structural biology
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更新日期：2010-08-01 00:00:00
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journal_title：Journal of structural biology
pub_type： 杂志文章
doi：10.1016/1047-8477(91)90030-z
更新日期：1991-08-01 00:00:00
abstract：:The structure of the smooth muscle contractile apparatus was studied using ultrarapid freezing followed by freeze substitution or by longitudinal freeze-fracture, deep-etch, and platinum-carbon replication. Freeze substitution minimises the detrimental effects of chemical fixation and freeze fracture eliminates them e...
journal_title：Journal of structural biology
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