PDBsum entry 4uyu

Hydrolase

PDB id: 4uyu

Contents

Protein chains

345 a.a.

Ligands

NAG ×2

Metals

IOD ×11

_CL ×2

Waters ×62

PDB id:

4uyu

Name:

Hydrolase

Title:

Structure of the wnt deacylase notum - crystal form i iodide complex - 2.3a

Structure:

Protein notum homolog. Chain: a, b. Synonym: notum. Engineered: yes. Mutation: yes. Other_details: glycosylated at n96

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: homo sapiens. Expression_system_taxid: 9606. Expression_system_cell_line: hek293t.

Resolution:

2.30Å R-factor: 0.209 R-free: 0.243

Authors:

M.Zebisch,E.Y.Jones

Key ref:

S.Kakugawa et al. (2015). Notum deacylates Wnt proteins to suppress signalling activity. Nature, 519, 187-192. PubMed id: 25731175 DOI: 10.1038/nature14259

Date:

03-Sep-14 Release date: 25-Feb-15

Protein chains

Q6P988  (NOTUM_HUMAN) -  Palmitoleoyl-protein carboxylesterase NOTUM from Homo sapiens

Seq: 496 a.a.

Struc: 345 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.3.1.1.98 - [Wnt protein] O-palmitoleoyl-L-serine hydrolase.
• Reaction: [Wnt protein]-O-(9Z)-hexadecenoyl-L-serine + H2O = [Wnt protein]-L-serine + (9Z)-hexadecenoate + H⁺

DOI no: 10.1038/nature14259

Nature 519:187-192 (2015)

PubMed id: 25731175

Notum deacylates Wnt proteins to suppress signalling activity.

S.Kakugawa, P.F.Langton, M.Zebisch, S.A.Howell, T.H.Chang, Y.Liu, T.Feizi, G.Bineva, N.O'Reilly, A.P.Snijders, E.Y.Jones, J.P.Vincent.

ABSTRACT

Signalling by Wnt proteins is finely balanced to ensure normal development and tissue homeostasis while avoiding diseases such as cancer. This is achieved in part by Notum, a highly conserved secreted feedback antagonist. Notum has been thought to act as a phospholipase, shedding glypicans and associated Wnt proteins from the cell surface. However, this view fails to explain specificity, as glypicans bind many extracellular ligands. Here we provide genetic evidence in Drosophila that Notum requires glypicans to suppress Wnt signalling, but does not cleave their glycophosphatidylinositol anchor. Structural analyses reveal glycosaminoglycan binding sites on Notum, which probably help Notum to co-localize with Wnt proteins. They also identify, at the active site of human and Drosophila Notum, a large hydrophobic pocket that accommodates palmitoleate. Kinetic and mass spectrometric analyses of human proteins show that Notum is a carboxylesterase that removes an essential palmitoleate moiety from Wnt proteins and thus constitutes the first known extracellular protein deacylase.