1o1d: Difference between revisions
New page: left|200px<br /><applet load="1o1d" size="450" color="white" frame="true" align="right" spinBox="true" caption="1o1d, resolution 70.00Å" /> '''MOLECULAR MODELS OF... |
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[[Image:1o1d.gif|left|200px]]<br /><applet load="1o1d" size=" | [[Image:1o1d.gif|left|200px]]<br /><applet load="1o1d" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1o1d, resolution 70.00Å" /> | caption="1o1d, resolution 70.00Å" /> | ||
'''MOLECULAR MODELS OF AVERAGED RIGOR CROSSBRIDGES FROM TOMOGRAMS OF INSECT FLIGHT MUSCLE'''<br /> | '''MOLECULAR MODELS OF AVERAGED RIGOR CROSSBRIDGES FROM TOMOGRAMS OF INSECT FLIGHT MUSCLE'''<br /> | ||
==Overview== | ==Overview== | ||
Electron tomography, correspondence analysis, molecular model building, and real-space refinement provide detailed 3-D structures for in situ | Electron tomography, correspondence analysis, molecular model building, and real-space refinement provide detailed 3-D structures for in situ myosin crossbridges in the nucleotide-free state (rigor), thought to represent the end of the power stroke. Unaveraged tomograms from a 25-nm longitudinal section of insect flight muscle preserved native structural variation. Recurring crossbridge motifs that repeat every 38.7 nm along the actin filament were extracted from the tomogram and classified by correspondence analysis into 25 class averages, which improved the signal to noise ratio. Models based on the atomic structures of actin and of myosin subfragment 1 were rebuilt to fit 11 class averages. A real-space refinement procedure was applied to quantitatively fit the reconstructions and to minimize steric clashes between domains introduced during the fitting. These combined procedures show that no single myosin head structure can fit all the in situ crossbridges. The validity of the approach is supported by agreement of these atomic models with fluorescent probe data from vertebrate muscle as well as with data from regulatory light chain crosslinking between heads of smooth muscle heavy meromyosin when bound to actin. | ||
==About this Structure== | ==About this Structure== | ||
1O1D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] and [http://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http:// | 1O1D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] and [http://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O1D OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Oryctolagus cuniculus]] | [[Category: Oryctolagus cuniculus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Chen, L | [[Category: Chen, L F.]] | ||
[[Category: Reedy, M | [[Category: Reedy, M C.]] | ||
[[Category: Reedy, M | [[Category: Reedy, M K.]] | ||
[[Category: Taylor, K | [[Category: Taylor, K A.]] | ||
[[Category: Winkler, H.]] | [[Category: Winkler, H.]] | ||
[[Category: actin-myosin complex in situ in muscle]] | [[Category: actin-myosin complex in situ in muscle]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:12:15 2008'' | ||
Revision as of 15:12, 21 February 2008
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MOLECULAR MODELS OF AVERAGED RIGOR CROSSBRIDGES FROM TOMOGRAMS OF INSECT FLIGHT MUSCLE
OverviewOverview
Electron tomography, correspondence analysis, molecular model building, and real-space refinement provide detailed 3-D structures for in situ myosin crossbridges in the nucleotide-free state (rigor), thought to represent the end of the power stroke. Unaveraged tomograms from a 25-nm longitudinal section of insect flight muscle preserved native structural variation. Recurring crossbridge motifs that repeat every 38.7 nm along the actin filament were extracted from the tomogram and classified by correspondence analysis into 25 class averages, which improved the signal to noise ratio. Models based on the atomic structures of actin and of myosin subfragment 1 were rebuilt to fit 11 class averages. A real-space refinement procedure was applied to quantitatively fit the reconstructions and to minimize steric clashes between domains introduced during the fitting. These combined procedures show that no single myosin head structure can fit all the in situ crossbridges. The validity of the approach is supported by agreement of these atomic models with fluorescent probe data from vertebrate muscle as well as with data from regulatory light chain crosslinking between heads of smooth muscle heavy meromyosin when bound to actin.
About this StructureAbout this Structure
1O1D is a Protein complex structure of sequences from Gallus gallus and Oryctolagus cuniculus. Full crystallographic information is available from OCA.
ReferenceReference
Molecular modeling of averaged rigor crossbridges from tomograms of insect flight muscle., Chen LF, Winkler H, Reedy MK, Reedy MC, Taylor KA, J Struct Biol. 2002 Apr-May;138(1-2):92-104. PMID:12160705
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