2QUB

Crystal structure of extracellular lipase LipA from Serratia marcescens

2QUB の概要

• エントリーDOI: 10.2210/pdb2qub/pdb
• 関連するPDBエントリー: 2QUA
• 分子名称: Extracellular lipase, CALCIUM ION (3 entities in total)
• 機能のキーワード: beta roll, alpha/beta hydrolase, helical hairpin, hydrolase
• 由来する生物種: Serratia marcescens
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 392354.55

構造登録者

Meier, R.,Baumann, U. (登録日: 2007-08-04, 公開日: 2007-08-28, 最終更新日: 2024-02-21)

主引用文献

Meier, R.,Drepper, T.,Svensson, V.,Jaeger, K.E.,Baumann, U.
A calcium-gated lid and a large beta-roll sandwich are revealed by the crystal structure of extracellular lipase from Serratia marcescens.
J.Biol.Chem., 282:31477-31483, 2007

PubMed Abstract: Lipase LipA from Serratia marcescens is a 613-amino acid enzyme belonging to family I.3 of lipolytic enzymes that has an important biotechnological application in the production of a chiral precursor for the coronary vasodilator diltiazem. Like other family I.3 lipases, LipA is secreted by Gram-negative bacteria via a type I secretion system and possesses 13 copies of a calcium binding tandem repeat motif, GGXGXDXUX (U, hydrophobic amino acids), in the C-terminal part of the polypeptide chain. The 1.8-A crystal structure of LipA reveals a close relation to eukaryotic lipases, whereas family I.1 and I.2 enzymes appear to be more distantly related. Interestingly, the structure shows for the N-terminal lipase domain a variation on the canonical alpha/beta hydrolase fold in an open conformation, where the putative lid helix is anchored by a Ca(2+) ion essential for activity. Another novel feature observed in this lipase structure is the presence of a helical hairpin additional to the putative lid helix that exposes a hydrophobic surface to the aqueous medium and might function as an additional lid. The tandem repeats form two separated parallel beta-roll domains that pack tightly against each other. Variations of the consensus sequence of the tandem repeats within the second beta-roll result in an asymmetric Ca(2+) binding on only one side of the roll. The analysis of the properties of the beta-roll domains suggests an intramolecular chaperone function.

PubMed: 17728256
DOI: 10.1074/jbc.M704942200

実験手法

X-RAY DIFFRACTION (1.8 Å)