1SN2

Crystal Structure of Sea Bream Transthyretin at 1.90A Resolution

1SN2 の概要

• エントリーDOI: 10.2210/pdb1sn2/pdb
• 関連するPDBエントリー: 1sn0 1sn5
• 分子名称: transthyretin, SULFATE ION (3 entities in total)
• 機能のキーワード: transport protein
• 由来する生物種: Sparus aurata (gilthead seabream)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 56206.38

構造登録者

Eneqvist, T.,Lundberg, E.,Karlsson, A.,Huang, S.,Cantos, C.R.,Power, D.M.,Sauer-Eriksson, A.E. (登録日: 2004-03-10, 公開日: 2004-08-03, 最終更新日: 2023-08-23)

主引用文献

Eneqvist, T.,Lundberg, E.,Karlsson, A.,Huang, S.,Santos, C.R.,Power, D.M.,Sauer-Eriksson, A.E.
High resolution crystal structures of piscine transthyretin reveal different binding modes for triiodothyronine and thyroxine.
J.Biol.Chem., 279:26411-26416, 2004

PubMed Abstract: Transthyretin (TTR) is an extracellular transport protein involved in the distribution of thyroid hormones and vitamin A. So far, TTR has only been found in vertebrates, of which piscine TTR displays the lowest sequence identity with human TTR (47%). Human and piscine TTR bind both thyroid hormones 3,5,3'-triiodo-l-thyronine (T(3)) and 3,5,3',5'-tetraiodo-l-thyronine (thyroxine, T(4)). Human TTR has higher affinity for T(4) than T(3), whereas the reverse holds for piscine TTR. X-ray structures of Sparus aurata (sea bream) TTR have been determined as the apo-protein at 1.75 A resolution and bound to ligands T(3) and T(4), both at 1.9 A resolution. The apo structure is similar to human TTR with structural changes only at beta-strand D. This strand forms an extended loop conformation similar to the one in chicken TTR. The piscine TTR.T(4) complex shows the T(4)-binding site to be similar but not identical to human TTR, whereas the TTR.T(3) complex shows the I3' halogen situated at the site normally occupied by the hydroxyl group of T(4). The significantly wider entrance of the hormone-binding channel in sea bream TTR, in combination with its narrower cavity, provides a structural explanation for the different binding affinities of human and piscine TTR to T(3) and T(4).

PubMed: 15082720
DOI: 10.1074/jbc.M313553200

実験手法

X-RAY DIFFRACTION (1.75 Å)