Linked Life Data

2164584

Source:http://linkedlifedata.com/resource/pubmed/id/2164584

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-8-23
pubmed:abstractText
The structure of cytochrome oxidase from beef heart mitochondria has been analysed by cryo-electron microscopy of vesicle crystals of the space group p22(1)2(1), with cell dimensions a = 102 A, b = 123 A, gamma = 90 degrees. Several methods of specimen preparation were applied to the vesicular two-dimensional crystals in the electron microscope, to ensure that the structure was preserved to the maximum resolution. The two most informative density maps were from specimens embedded in ice and from negative staining in a 1:1 mixture of glucose and uranyl acetate. The three-dimensional structure of the ice-embedded molecule shows a single, well resolved, but convoluted density, which represents in size and shape one cytochrome oxidase dimer. At the bottom of the molecule, a substantial part of the protein is embedded in the lipid bilayer of the vesicle. The molecule then extends upwards, out of the bilayer, into the internal space within the vesicle. Here, the structure first passes through a region within the molecule containing a hollow cavity that lies roughly at the centre of mass of the dimer, and then branches into two well-resolved halves at some distance from the membrane. The negatively stained structure, in contrast, shows a stain-excluding region in the centre of the vesicle at the level of the cavity in the ice-embedded structure, but otherwise has a similar overall external shape. In addition, there is a small rotation of the whole molecule by approximately 25 degrees relative to the orientation of ice-embedded specimens. We interpret these differences to mean that the central cavity seen in the ice-embedded structure is too small to allow the stain to penetrate during the drying process and that the drying process causes the rotation. The structures described here are consistent with one another and allow an interpretation at higher resolution than from previous work.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
214
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
237-51
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Electron cryo-microscopic analysis of crystalline cytochrome oxidase.
pubmed:affiliation
Medical Research Council, Laboratory of Molecular Biology, Cambridge, U.K.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't