1GKA

The molecular basis of the coloration mechanism in lobster shell. beta-crustacyanin at 3.2 A resolution

1GKA の概要

• エントリーDOI: 10.2210/pdb1gka/pdb
• 関連するPDBエントリー: 1H91
• 分子名称: CRUSTACYANIN A1 SUBUNIT, CRUSTACYANIN A2 SUBUNIT, ASTAXANTHIN, ... (7 entities in total)
• 機能のキーワード: lipocalin, crustacyanin, lobster, astaxanthin, bathochromic, coloration
• 由来する生物種: HOMARUS GAMMARUS (EUROPEAN LOBSTER); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 41971.31

構造登録者

Cianci, M.,Rizkallah, P.J.,Olczak, A.,Raftery, J.,Chayen, N.E.,Zagalsky, P.F.,Helliwell, J.R. (登録日: 2001-08-10, 公開日: 2002-08-08, 最終更新日: 2024-10-16)

主引用文献

Cianci, M.,Rizkallah, P.,Olczak, A.,Raftery, J.,Chayen, N.,Zagalsky, P.,Helliwell, J.
The Molecular Basis of the Coloration Mechanism in Lobster Shell: Beta -Crustacyanin at 3.2-A Resolution
Proc.Natl.Acad.Sci.USA, 99:9795-, 2002

PubMed Abstract: The binding of the carotenoid astaxanthin (AXT) in the protein multimacromolecular complex crustacyanin (CR) is responsible for the blue coloration of lobster shell. The structural basis of the bathochromic shift mechanism has long been elusive. A change in color occurs from the orange red of the unbound dilute AXT (lambda(max) 472 nm in hexane), the well-known color of cooked lobster, to slate blue in the protein-bound live lobster state (lambda(max) 632 nm in CR). Intriguingly, extracted CR becomes red on dehydration and on rehydration goes back to blue. Recently, the innovative use of softer x-rays and xenon derivatization yielded the three-dimensional structure of the A(1) apoprotein subunit of CR, confirming it as a member of the lipocalin superfamily. That work provided the molecular replacement search model for a crystal form of the beta-CR holo complex, that is an A(1) with A(3) subunit assembly including two bound AXT molecules. We have thereby determined the structure of the A(3) molecule de novo. Lobster has clearly evolved an intricate structural mechanism for the coloration of its shell using AXT and a bathochromic shift. Blue/purple AXT proteins are ubiquitous among invertebrate marine animals, particularly the Crustacea. The three-dimensional structure of beta-CR has identified the protein contacts and structural alterations needed for the AXT color regulation mechanism.

PubMed: 12119396
DOI: 10.1073/PNAS.152088999

実験手法

X-RAY DIFFRACTION (3.23 Å)