2W8V

SPT with PLP, N100W

2W8V の概要

• エントリーDOI: 10.2210/pdb2w8v/pdb
• 関連するPDBエントリー: 2W8J 2W8T 2W8U 2W8W
• 分子名称: SERINE PALMITOYLTRANSFERASE, PYRIDOXAL-5'-PHOSPHATE (3 entities in total)
• 機能のキーワード: transferase
• 由来する生物種: PSEUDOMONAS PAUCIMOBILIS
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 46349.80

構造登録者

Raman, M.C.C.,Johnson, K.A.,Campopiano, D.J.,Naismith, J.H. (登録日: 2009-01-19, 公開日: 2009-01-27, 最終更新日: 2025-04-09)

主引用文献

Raman, M.C.C.,Johnson, K.A.,Yard, B.A.,Lowther, J.,Carter, L.G.,Naismith, J.H.,Campopiano, D.J.
The External-Aldimine Form of Serine Palmitoyltranserase; Structural, Kinetic and Spectroscopic Analysis of the Wild-Type Enzyme and Hsan1 Mutant Mimics.
J.Biol.Chem., 284:17328-, 2009

PubMed Abstract: Sphingolipid biosynthesis begins with the condensation of L-serine and palmitoyl-CoA catalyzed by the PLP-dependent enzyme serine palmitoyltransferase (SPT). Mutations in human SPT cause hereditary sensory autonomic neuropathy type 1, a disease characterized by loss of feeling in extremities and severe pain. The human enzyme is a membrane-bound hetereodimer, and the most common mutations are located in the enzymatically incompetent monomer, suggesting a "dominant" or regulatory effect. The molecular basis of how these mutations perturb SPT activity is subtle and is not simply loss of activity. To further explore the structure and mechanism of SPT, we have studied the homodimeric bacterial enzyme from Sphingomonas paucimobilis. We have analyzed two mutants (N100Y and N100W) engineered to mimic the mutations seen in hereditary sensory autonomic neuropathy type 1 as well as a third mutant N100C designed to mimic the wild-type human SPT. The N100C mutant appears fully active, whereas both N100Y and N100W are significantly compromised. The structures of the holoenzymes reveal differences around the active site and in neighboring secondary structure that transmit across the dimeric interface in both N100Y and N100W. Comparison of the l-Ser external aldimine structures of both native and N100Y reveals significant differences that hinder the movement of a catalytically important Arg(378) residue into the active site. Spectroscopic analysis confirms that both N100Y and N100W mutants subtly affect the chemistry of the PLP. Furthermore, the N100Y and R378A mutants appear less able to stabilize a quinonoid intermediate. These data provide the first experimental insight into how the most common disease-associated mutations of human SPT may lead to perturbation of enzyme activity.

PubMed: 19376777
DOI: 10.1074/JBC.M109.008680

実験手法

X-RAY DIFFRACTION (1.43 Å)