5C1C

Crystal Structure of the Pectin Methylesterase from Aspergillus niger in Deglycosylated Form

5C1C の概要

• エントリーDOI: 10.2210/pdb5c1c/pdb
• 関連するPDBエントリー: 5C1E
• 分子名称: Pectinesterase, SULFATE ION, CHLORIDE ION, ... (6 entities in total)
• 機能のキーワード: parallel beta helix, pectin methylesterase, hydrolase
• 由来する生物種: Aspergillus niger (strain ATCC 1015 / CBS 113.46 / FGSC A1144 / LSHB Ac4 / NCTC 3858a / NRRL 328 / USDA 3528.7)
• 細胞内の位置: Secreted : G3YAL0
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 32644.37

構造登録者

Jameson, G.B.,Williams, M.A.K.,Loo, T.S.,Kent, L.M.,Melton, L.D.,Mercadante, D. (登録日: 2015-06-13, 公開日: 2015-07-01, 最終更新日: 2024-11-20)

主引用文献

Kent, L.M.,Loo, T.S.,Melton, L.D.,Mercadante, D.,Williams, M.A.,Jameson, G.B.
Structure and Properties of a Non-processive, Salt-requiring, and Acidophilic Pectin Methylesterase from Aspergillus niger Provide Insights into the Key Determinants of Processivity Control.
J.Biol.Chem., 291:1289-1306, 2016

PubMed Abstract: Many pectin methylesterases (PMEs) are expressed in plants to modify plant cell-wall pectins for various physiological roles. These pectins are also attacked by PMEs from phytopathogens and phytophagous insects. The de-methylesterification by PMEs of the O6-methyl ester groups of the homogalacturonan component of pectin, exposing galacturonic acids, can occur processively or non-processively, respectively, describing sequential versus single de-methylesterification events occurring before enzyme-substrate dissociation. The high resolution x-ray structures of a PME from Aspergillus niger in deglycosylated and Asn-linked N-acetylglucosamine-stub forms reveal a 10⅔-turn parallel β-helix (similar to but with less extensive loops than bacterial, plant, and insect PMEs). Capillary electrophoresis shows that this PME is non-processive, halophilic, and acidophilic. Molecular dynamics simulations and electrostatic potential calculations reveal very different behavior and properties compared with processive PMEs. Specifically, uncorrelated rotations are observed about the glycosidic bonds of a partially de-methyl-esterified decasaccharide model substrate, in sharp contrast to the correlated rotations of processive PMEs, and the substrate-binding groove is negatively not positively charged.

PubMed: 26567911
DOI: 10.1074/jbc.M115.673152

実験手法

X-RAY DIFFRACTION (1.8 Å)