1PPA

THE CRYSTAL STRUCTURE OF A LYSINE 49 PHOSPHOLIPASE A2 FROM THE VENOM OF THE COTTONMOUTH SNAKE AT 2.0 ANGSTROMS RESOLUTION

1PPA の概要

• エントリーDOI: 10.2210/pdb1ppa/pdb
• 分子名称: PHOSPHOLIPASE A2, ANILINE (3 entities in total)
• 機能のキーワード: hydrolase(carboxylic esterase)
• 由来する生物種: Agkistrodon piscivorus piscivorus (eastern cottonmouth)
• 細胞内の位置: Secreted: P04361
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 14080.45

構造登録者

Holland, D.R.,Clancy, L.L.,Muchmore, S.W.,Rydel, T.J.,Einspahr, H.M.,Finzel, B.C.,Heinrikson, R.L.,Watenpaugh, K.D. (登録日: 1991-10-29, 公開日: 1994-01-31, 最終更新日: 2024-10-23)

主引用文献

Holland, D.R.,Clancy, L.L.,Muchmore, S.W.,Ryde, T.J.,Einspahr, H.M.,Finzel, B.C.,Heinrikson, R.L.,Watenpaugh, K.D.
The crystal structure of a lysine 49 phospholipase A2 from the venom of the cottonmouth snake at 2.0-A resolution.
J.Biol.Chem., 265:17649-17656, 1990

PubMed Abstract: The crystal structure of a lysine 49 variant phospholipase A2 (K49 PLA2) has been determined at 2.0-A resolution. This particular phospholipase A2, purified from the venom of the eastern cottonmouth (Agkistrodon piscivorus piscivorus), a North American pit viper, differs significantly from others studied crystallographically because of replacement of the aspartate residue at position 49, whose side chain is important in calcium binding, by lysine. The crystallographic analysis of K49 PLA2 was undertaken to assess the structural ramifications of this substitution, particularly as they affect the binding mechanism of both the calcium cofactor and the phospholipid substrate. The protein crystals are tetragonal, space group P4(1)2(1)2, with unit cell dimensions of a = b = 71.7 (1) and c = 57.8 (3) A. Preliminary phases were obtained by molecular replacement techniques with a search model derived from the refined 2.5-A structure of a rattle-snake venom phospholipase A2 (Brunie, S., Bolin, J., Gewirth, D., and Sigler, P. B. (1985) J. Biol. Chem. 260, 9742-9749). The starting model gave an initial crystallographic RF of 0.526 (RF = sigma parallel to Fo /-/ Fc parallel to /sigma/Fo/). The structure was refined against all data to 2.0-A resolution. The final RF is 0.158. The final model includes 150 discrete water molecules. The K49 PLA2 model is composed primarily of alpha-helices joined by loops, some of which are quite extensive. Although dissimilarities are observed in the loop regions, the helical portions are very similar to those in other known phospholipase A2 structures. The proposed catalytic center (His48, Tyr73, and Asp99) is also structurally conserved. The region in K49 PLA2 corresponding to the calcium-binding site in other phospholipases A2 is occupied by the epsilon-amino group of lysine 49.

PubMed: 2120215

実験手法

X-RAY DIFFRACTION (2 Å)