7LZ3

Computational design of constitutively active cGAS

Summary for 7LZ3

• Entry DOI: 10.2210/pdb7lz3/pdb
• Descriptor: Cyclic GMP-AMP synthase, ZINC ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: de novo designed, constitutive mutant, cgas, de novo protein
• Biological source: synthetic construct
• Total number of polymer chains: 2
• Total formula weight: 85235.30

Authors

Dowling, Q.,Volkman, H.E.,Gray, E.E.,Ovchinnikov, S.,Cambier, S.,Bera, A.K.,Bick, M.,Kang, A.,Stetson, D.B.,King, N.P. (deposition date: 2021-03-08, release date: 2022-03-16, Last modification date: 2024-05-22)

Primary citation

Dowling, Q.M.,Volkman, H.E.,Gray, E.E.,Ovchinnikov, S.,Cambier, S.,Bera, A.K.,Sankaran, B.,Johnson, M.R.,Bick, M.J.,Kang, A.,Stetson, D.B.,King, N.P.
Computational design of constitutively active cGAS.
Nat.Struct.Mol.Biol., 30:72-80, 2023

PubMed Abstract: Cyclic GMP-AMP synthase (cGAS) is a pattern recognition receptor critical for the innate immune response to intracellular pathogens, DNA damage, tumorigenesis and senescence. Binding to double-stranded DNA (dsDNA) induces conformational changes in cGAS that activate the enzyme to produce 2'-3' cyclic GMP-AMP (cGAMP), a second messenger that initiates a potent interferon (IFN) response through its receptor, STING. Here, we combined two-state computational design with informatics-guided design to create constitutively active, dsDNA ligand-independent cGAS (CA-cGAS). We identified CA-cGAS mutants with IFN-stimulating activity approaching that of dsDNA-stimulated wild-type cGAS. DNA-independent adoption of the active conformation was directly confirmed by X-ray crystallography. In vivo expression of CA-cGAS in tumor cells resulted in STING-dependent tumor regression, demonstrating that the designed proteins have therapeutically relevant biological activity. Our work provides a general framework for stabilizing active conformations of enzymes and provides CA-cGAS variants that could be useful as genetically encoded adjuvants and tools for understanding inflammatory diseases.

PubMed: 36593311
DOI: 10.1038/s41594-022-00862-z

Experimental method

X-RAY DIFFRACTION (2.18 Å)