PDBsum entry 6nao

Transferase/transferase inhibitor

PDB id: 6nao

Contents

Protein chains

358 a.a.

Ligands

KHM ×2

Metals

_ZN ×2

Waters ×22

PDB id:

6nao

Name:

Transferase/transferase inhibitor

Title:

Discovery of a high affinity inhibitor of cgas

Structure:

Cyclic gmp-amp synthase. Chain: a, b. Fragment: unp residues 161-522. Synonym: h-cgas,2'3'-cgamp synthase,mab-21 domain-containing protein 1. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: cgas, c6orf150, mb21d1. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

3.23Å R-factor: 0.219 R-free: 0.253

Authors:

J.Hall

Key ref:

J.Hall et al. (2017). Discovery of PF-06928215 as a high affinity inhibitor of cGAS enabled by a novel fluorescence polarization assay. PLoS One, 12, e0184843. PubMed id: 28934246

Date:

06-Dec-18 Release date: 19-Dec-18

Supersedes:

5v8n

Protein chains

Q8N884  (CGAS_HUMAN) -  Cyclic GMP-AMP synthase from Homo sapiens

Seq: 522 a.a.

Struc: 358 a.a.

Enzyme reactions

• Enzyme class: E.C.2.7.7.86 - cyclic GMP-AMP synthase.
• Reaction: GTP + ATP = 2',3'-cGAMP + 2 diphosphate

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

reference

PLoS One 12:e0184843 (2017)

PubMed id: 28934246

Discovery of PF-06928215 as a high affinity inhibitor of cGAS enabled by a novel fluorescence polarization assay.

J.Hall, A.Brault, F.Vincent, S.Weng, H.Wang, D.Dumlao, A.Aulabaugh, D.Aivazian, D.Castro, M.Chen, J.Culp, K.Dower, J.Gardner, S.Hawrylik, D.Golenbock, D.Hepworth, M.Horn, L.Jones, P.Jones, E.Latz, J.Li, L.L.Lin, W.Lin, D.Lin, F.Lovering, N.Niljanskul, R.Nistler, B.Pierce, O.Plotnikova, D.Schmitt, S.Shanker, J.Smith, W.Snyder, T.Subashi, J.Trujillo, E.Tyminski, G.Wang, J.Wong, B.Lefker, L.Dakin, K.Leach.

ABSTRACT

Cyclic GMP-AMP synthase (cGAS) initiates the innate immune system in response to cytosolic dsDNA. After binding and activation from dsDNA, cGAS uses ATP and GTP to synthesize 2', 3' -cGAMP (cGAMP), a cyclic dinucleotide second messenger with mixed 2'-5' and 3'-5' phosphodiester bonds. Inappropriate stimulation of cGAS has been implicated in autoimmune disease such as systemic lupus erythematosus, thus inhibition of cGAS may be of therapeutic benefit in some diseases; however, the size and polarity of the cGAS active site makes it a challenging target for the development of conventional substrate-competitive inhibitors. We report here the development of a high affinity (KD = 200 nM) inhibitor from a low affinity fragment hit with supporting biochemical and structural data showing these molecules bind to the cGAS active site. We also report a new high throughput cGAS fluorescence polarization (FP)-based assay to enable the rapid identification and optimization of cGAS inhibitors. This FP assay uses Cy5-labelled cGAMP in combination with a novel high affinity monoclonal antibody that specifically recognizes cGAMP with no cross reactivity to cAMP, cGMP, ATP, or GTP. Given its role in the innate immune response, cGAS is a promising therapeutic target for autoinflammatory disease. Our results demonstrate its druggability, provide a high affinity tool compound, and establish a high throughput assay for the identification of next generation cGAS inhibitors.