1ST3

THE CRYSTAL STRUCTURE OF THE BACILLUS LENTUS ALKALINE PROTEASE, SUBTILISIN BL, AT 1.4 ANGSTROMS RESOLUTION

1ST3 の概要

• エントリーDOI: 10.2210/pdb1st3/pdb
• 分子名称: SUBTILISIN BL, CALCIUM ION (3 entities in total)
• 機能のキーワード: serine protease
• 由来する生物種: Bacillus lentus
• 細胞内の位置: Secreted: P29599
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 26910.69

構造登録者

Goddette, D.W. (登録日: 1991-11-22, 公開日: 1994-01-31, 最終更新日: 2024-02-14)

主引用文献

Goddette, D.W.,Paech, C.,Yang, S.S.,Mielenz, J.R.,Bystroff, C.,Wilke, M.E.,Fletterick, R.J.
The crystal structure of the Bacillus lentus alkaline protease, subtilisin BL, at 1.4 A resolution.
J.Mol.Biol., 228:580-595, 1992

PubMed Abstract: The crystal structure of subtilisin BL, an alkaline protease from Bacillus lentus with activity at pH 11, has been determined to 1.4 A resolution. The structure was solved by molecular replacement starting with the 2.1 A structure of subtilisin BPN' followed by molecular dynamics refinement using X-PLOR. A final crystallographic R-factor of 19% overall was obtained. The enzyme possesses stability at high pH, which is a result of the high pI of the protein. Almost all of the acidic side-chains are involved in some type of electrostatic interaction (ion pairs, calcium binding, etc.). Furthermore, three of seven tyrosine residues have potential partners for forming salt bridges. All of the potential partners are arginine with a pK around 12. Lysine would not function well in a salt bridge with tyrosine as it deprotonates at around the same pH as tyrosine ionizes. Stability at high pH is acquired in part from the pI of the protein, but also from the formation of salt bridges (which would affect the pI). The overall structure of the enzyme is very similar to other subtilisins and shows that the subtilisin fold is more highly conserved than would be expected from the differences in amino acid sequence. The amino acid side-chains in the hydrophobic core are not conserved, though the inter-residue interactions are. Finally, one third of the serine side-chains in the protein have multiple conformations. This presents an opportunity to correlate computer simulations with observed occupancies in the crystal structure.

PubMed: 1453465
DOI: 10.1016/0022-2836(92)90843-9

実験手法

X-RAY DIFFRACTION (1.4 Å)