Open AccessJournal Article
The mechanism of iron uptake by transferrins: the structure of an 18kDa NII-domain fragment from duck ovotransferrin at 2.3 Å resolution
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TLDR
The molecular structure of an iron-containing 18 kDa fragment of duck ovotransferrin has been elucidated by protein crystallographic techniques at 2.3 A resolution and strongly suggests that the histidine residue present at the iron binding site of the intact protein and arising from the second interdomain connecting strand has been removed during the preparative proteolysis.Abstract:
The molecular structure of an iron-containing 18 kDa fragment of duck ovotransferrin, obtained by proteolysis of the intact protein, has been elucidated by protein crystallographic techniques at 2.3 A resolution. This structure supports a mechanism of iron uptake in the intact protein whereby the binding of the synergistic (bi)carbonate anion is followed by binding of the metal with the lobe in the open configuration. These stages are then followed by domain closure in which the aspartic acid residue plays a further key role, by forming an interdomain hydrogen-bond interaction in addition to serving as a ligand to the iron. This essential dual role is highlighted by model building studies on the C-terminal lobe of a known human variant. In this variant a mutation of a glycine by an arginine residue enables the aspartic acid to form an ion pair and reduce its effectiveness for both metal binding and domain closure. The X-ray structure of the 18 kDa fragment strongly suggests that the histidine residue present at the iron binding site of the intact protein and arising from the second interdomain connecting strand has been removed during the preparative proteolysis.read more
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Structural and Functional Aspects of Metal Sites in Biology
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Transferrin as a metal ion mediator.
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Cubanecarboxylic Acids. Crystal Engineering Considerations and the Role of C−H···O Hydrogen Bonds in Determining O−H···O Networks
TL;DR: A family of 4-substituted 1-cubanecarboxylic acids have been synthesized and their X-ray crystal structures analyzed as discussed by the authors, and the rare syn-anti O−H−O catemer 6 is a recurring pattern in this series of compounds.
Book ChapterDOI
Structure and Reactivity of Transferrins
TL;DR: This chapter provides an overview of structure and reactivity of transferrins, a family of metal-binding proteins having significant role in biological research.
References
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Book
Principles of Protein Structure
TL;DR: The present work focuses on the development of a model for the transition of the Amino Acid Sequence from Nucleic Acids to Polypeptides to Protein Structures, and the role that this model plays in the Evolution of Proteins.
Journal ArticleDOI
Different segmental flexibility of human serum transferrin and lactoferrin
TL;DR: X-ray diffraction studies show that the diferric (holo) forms of human serum transferrin and lactoferrin have almost the same conformation in crystal, but in solution, the two proteins exhibit different characteristics.
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