1GV8

18 kDa fragment of N-II domain of duck ovotransferrin

1GV8 の概要

• エントリーDOI: 10.2210/pdb1gv8/pdb
• 関連するPDBエントリー: 1AOV 1DOT 1OVB
• 分子名称: OVOTRANSFERRIN, GLYCINE, CARBONATE ION, ... (5 entities in total)
• 機能のキーワード: iron transport, glycoprotein, metal-binding
• 由来する生物種: ANAS PLATYRHYNCHOS (COMMON DUCK)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17549.55

構造登録者

Kuser, P.,Hall, D.R.,Haw, M.L.,Neu, M.,Lindley, P.F. (登録日: 2002-02-07, 公開日: 2002-02-12, 最終更新日: 2024-10-16)

主引用文献

Kuser, P.,Hall, D.R.,Haw, M.L.,Neu, M.,Evans, R.,Lindley, P.F.
The Mechanism of Iron Uptake by Transferrins: The X-Ray Structures of the 18 kDa Nii Domain Fragment of Duck Ovotransferrin and its Nitrilotriacetate Complex
Acta Crystallogr.,Sect.D, 58:777-, 2002

PubMed Abstract: In a previous paper [Lindley et al. (1993), Acta Cryst. D49, 292-304], the X-ray structure analysis of the 18 kDa fragment of duck ovotransferrin, corresponding to the NII domain of the intact protein, was reported at a resolution of 2.3 A. In this structure, the Fe(III) cation binds to two tyrosine residues and the synergistic carbonate anion in an identical manner to that found in the intact protein. However, the aspartate and histidine residues, normally involved in iron binding in transferrins, are absent in the fragment and it was not possible to unequivocally define what had replaced them. The electron density was tentatively assigned to be a mixture of peptides, presumably resulting from the proteolytic preparation of the fragment, binding to the iron through their amino and carboxylate termini. A more recent X-ray analysis of the fragment, from a different preparation, has resulted in a structure at 1.95 A, in which glycine appears to be the predominant residue bound to the cation. In an alternative attempt to clarify the binding of iron to the 18 kDa fragment, the metal was removed by dialysis and replaced in the form of ferric nitrilotriacetate. Crystallization of this complex has resulted in an X-ray structure at 1.90 A in which the Fe(III) is bound to the synergistic carbonate anion and only one tyrosine residue in a manner almost identical to the intact protein. The carboxylate groups and the tertiary amino group of the nitrilotriacetate occupy the remaining coordination sites. The second tyrosine residue, Tyr95, is not bound directly to the iron. The implication of these structures with respect to the mechanism of iron binding by the transferrins is addressed.

PubMed: 11976488
DOI: 10.1107/S0907444902003724

実験手法

X-RAY DIFFRACTION (1.95 Å)