PDBsum entry 5fdq

Oxidoreductase/inhibitor

PDB id: 5fdq

Contents

Protein chains

551 a.a.

Ligands

NAG-NAG ×2

NAG-NAG-MAN

COH ×2

AKR ×2

60A ×2

BOG

NAG ×3

Waters ×1144

PDB id:

5fdq

Name:

Oxidoreductase/inhibitor

Title:

Murine cox-2 s530t mutant

Structure:

Prostaglandin g/h synthase 2. Chain: a, b. Synonym: cyclooxygenase-2,cox-2,glucocorticoid-regulated inflammatory cyclooxygenase,gripghs,macrophage activation-associated marker protein p71/73,pes-2,phs ii,prostaglandin h2 synthase 2,pghs-2, prostaglandin-endoperoxide synthase 2,tis10 protein. Engineered: yes. Mutation: yes

Source:

Mus musculus. Mouse. Organism_taxid: 10090. Gene: ptgs2, cox-2, cox2, pghs-b, tis10. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108

Resolution:

1.90Å R-factor: 0.155 R-free: 0.191

Authors:

M.J.Lucido,B.J.Orlando,M.G.Malkowski

Key ref:

M.J.Lucido et al. (2016). Crystal Structure of Aspirin-Acetylated Human Cyclooxygenase-2: Insight into the Formation of Products with Reversed Stereochemistry. Biochemistry, 55, 1226-1238. PubMed id: 26859324 DOI: 10.1021/acs.biochem.5b01378

Date:

16-Dec-15 Release date: 16-Mar-16

Protein chains

Q05769  (PGH2_MOUSE) -  Prostaglandin G/H synthase 2 from Mus musculus

Seq: 604 a.a.

Struc: 551 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.1.14.99.1 - prostaglandin-endoperoxide synthase.
• Reaction: (5Z,8Z,11Z,14Z)-eicosatetraenoate + AH2 + 2 O2 = prostaglandin H2 + A + H2O

(5Z,8Z,11Z,14Z)-eicosatetraenoate + AH2 + 2 × O2 = prostaglandin H2 + + H2O (Bound ligand (Het Group name = COH) matches with 51.11% similarity)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1021/acs.biochem.5b01378

Biochemistry 55:1226-1238 (2016)

PubMed id: 26859324

Crystal Structure of Aspirin-Acetylated Human Cyclooxygenase-2: Insight into the Formation of Products with Reversed Stereochemistry.

M.J.Lucido, B.J.Orlando, A.J.Vecchio, M.G.Malkowski.

ABSTRACT

Aspirin and other nonsteroidal anti-inflammatory drugs target the cyclooxygenase enzymes (COX-1 and COX-2) to block the formation of prostaglandins. Aspirin is unique in that it covalently modifies each enzyme by acetylating Ser-530 within the cyclooxygenase active site. Acetylation of COX-1 leads to complete loss of activity, while acetylation of COX-2 results in the generation of the monooxygenated product 15(R)-hydroxyeicosatetraenoic acid (15R-HETE). Ser-530 has also been shown to influence the stereochemistry for the addition of oxygen to the prostaglandin product. We determined the crystal structures of S530T murine (mu) COX-2, aspirin-acetylated human (hu) COX-2, and huCOX-2 in complex with salicylate to 1.9, 2.0, and 2.4 Å, respectively. The structures reveal that (1) the acetylated Ser-530 completely blocks access to the hydrophobic groove, (2) the observed binding pose of salicylate is reflective of the enzyme-inhibitor complex prior to acetylation, and (3) the observed Thr-530 rotamer in the S530T muCOX-2 crystal structure does not impede access to the hydrophobic groove. On the basis of these structural observations, along with functional analysis of the S530T/G533V double mutant, we propose a working hypothesis for the generation of 15R-HETE by aspirin-acetylated COX-2. We also observe differential acetylation of COX-2 purified in various detergent systems and nanodiscs, indicating that detergent and lipid binding within the membrane-binding domain of the enzyme alters the rate of the acetylation reaction in vitro.