Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-12-19
pubmed:abstractText
Most organisms depend on iron as a co-factor for proteins catalyzing redox reactions. Iron is, however, a difficult element for cells to deal with, as it is insoluble in its ferric (Fe3+) form and potentially toxic in its ferrous (Fe2+) form. Thus, in vertebrates iron is transported through the circulation bound to transferrin (Tf) and delivered to cells through an endocytotic cycle involving the transferrin receptor (TfR). We have previously presented a model for the Tf-TfR complex in its iron-bearing form, the diferric transferrin (dTf)-TfR complex [Cheng, Y., Zak, O., Aisen, P., Harrison, S.C., Walz, T., 2004. Structure of the human transferrin receptor-transferrin complex. Cell 116, 565-576]. We have now calculated a single particle reconstruction for the complex in its iron-free form, the apo-transferrin (apoTf)-TfR complex. The same density map was obtained by aligning raw particle images or class averages of the vitrified apoTf-TfR complex to reference models derived from the structures of the dTf-TfR or apoTf-TfR complex. We were unable to improve the resolution of the apoTf-TfR density map beyond 16A, most likely because of significant structural variability of Tf in its iron-free state. The density map does, however, support the model for the apoTf-TfR we previously proposed based on the dTf-TfR complex structure, and it suggests that receptor-bound apoTf prefers to adopt an open conformation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1047-8477
pubmed:author
pubmed:issnType
Print
pubmed:volume
152
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
204-10
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Single particle reconstruction of the human apo-transferrin-transferrin receptor complex.
pubmed:affiliation
Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA. ycheng@hms.harvard.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural