1Z24

The molecular structure of insecticyanin from the tobacco hornworm Manduca sexta L. at 2.6 A resolution.

1Z24 の概要

• エントリーDOI: 10.2210/pdb1z24/pdb
• 分子名称: Insecticyanin A form, BILIVERDIN IX GAMMA CHROMOPHORE (2 entities in total)
• 機能のキーワード: blue biliprotein, ins-a, chromophore binding., lipid binding protein
• 由来する生物種: Manduca sexta (tobacco hornworm)
• 細胞内の位置: Secreted: P00305
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 21988.67

構造登録者

Holden, H.M.,Rypniewski, W.R.,Law, J.H.,Rayment, I. (登録日: 2005-03-07, 公開日: 2005-04-05, 最終更新日: 2024-10-30)

主引用文献

Holden, H.M.,Rypniewski, W.R.,Law, J.H.,Rayment, I.
The molecular structure of insecticyanin from the tobacco hornworm Manduca sexta L. at 2.6 A resolution.
Embo J., 6:1565-1570, 1987

PubMed Abstract: Insecticyanin, a blue biliprotein isolated from the tobacco hornworm Manduca sexta L., is involved in insect camouflage. Its three-dimensional structure has now been solved to 2.6 A resolution using the techniques of multiple isomorphous replacement, non-crystallographic symmetry averaging about a local 2-fold rotation axis and solvent flattening. All 189 amino acids have been fitted to the electron density map. The map clearly shows that insecticyanin is a tetramer with one of its molecular 2-fold axes coincident to a crystallographic dyad. The individual subunits have overall dimensions of 44 A X 37 A X 40 A and consist primarily of an eight-stranded anti-parallel beta-barrel flanked on one side by a 4.5-turn alpha-helix. Interestingly the overall three-dimensional fold of the insecticyanin subunit shows remarkable similarity to the structural motifs of bovine beta-lactoglobulin and the human serum retinol-binding protein. The electron density attributable to the chromophore is unambiguous and shows that it is indeed the gamma-isomer of biliverdin. The biliverdin lies towards the open end of the beta-barrel with its two propionate side chains pointing towards the solvent and it adopts a rather folded conformation, much like a heme.

PubMed: 3608987

実験手法

X-RAY DIFFRACTION (2.6 Å)