5Z9O

The crystal structure of Cyclopropane-fatty-acyl-phospholipid synthase from Lactobacillus acidophilus

5Z9O の概要

• エントリーDOI: 10.2210/pdb5z9o/pdb
• 分子名称: Cyclopropane-fatty-acyl-phospholipid synthase, CARBONATE ION, L-ALPHA-PHOSPHATIDYL-BETA-OLEOYL-GAMMA-PALMITOYL-PHOSPHATIDYLETHANOLAMINE, ... (4 entities in total)
• 機能のキーワード: cyclopropane-fatty-acyl-phospholipid synthase, phosphatidyl ethanolamine, bicarbonate ion, carbocation mechanism, lipid binding protein, transferase
• 由来する生物種: Lactobacillus acidophilus (strain ATCC 700396 / NCK56 / N2 / NCFM)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 93600.01

構造登録者

Pan, C.L.,Ma, Y.L.,Wang, Q.H. (登録日: 2018-02-04, 公開日: 2019-03-06, 最終更新日: 2023-11-22)

主引用文献

Ma, Y.,Pan, C.,Wang, Q.
Crystal structure of bacterial cyclopropane-fatty-acyl-phospholipid synthase with phospholipid.
J.Biochem., 166:139-147, 2019

PubMed Abstract: The lipids containing cyclopropane-fatty-acid (CFA) protect bacteria from adverse conditions such as acidity, freeze-drying desiccation and exposure to pollutants. CFA is synthesized when cyclopropane-fatty-acyl-phospholipid synthase (CFA synthase, CFAS) transfers a methylene group from S-adenosylmethionine (SAM) across the cis double bonds of unsaturated fatty acyl chains. Here, we reported a 2.7-Å crystal structure of CFAS from Lactobacillus acidophilus. The enzyme is composed of N- and C-terminal domain, which belong to the sterol carrier protein and methyltransferase superfamily, respectively. A phospholipid in the substrate binding site and a bicarbonate ion (BCI) acting as a general base in the active site were discovered. To elucidate the mechanism, a docking experiment using CFAS from L. acidophilus and SAM was carried out. The analysis of this structure demonstrated that three groups, the carbons from the substrate, the BCI and the methyl of S(CHn)3 group, were close enough to form a cyclopropane ring with the help of amino acids in the active site. Therefore, the structure supports the hypothesis that CFAS from L. acidophilus catalyzes methyl transfer via a carbocation mechanism. These findings provide a structural basis to more deeply understand enzymatic cyclopropanation.

PubMed: 30828715
DOI: 10.1093/jb/mvz018

実験手法

X-RAY DIFFRACTION (2.7 Å)