4K8V

Structure of cyclic GMP-AMP Synthase (cGAS)

Summary for 4K8V

• Entry DOI: 10.2210/pdb4k8v/pdb
• Related: 4K96 4K97 4K98 4K99 4K9A 4K9B
• Descriptor: Cyclic GMP-AMP synthase, ZINC ION (3 entities in total)
• Functional Keywords: nucleotidyltransferase, dna, transferase
• Biological source: Mus musculus (mouse)
• Cellular location: Cytoplasm, cytosol: Q8C6L5
• Total number of polymer chains: 4
• Total formula weight: 170310.12

Authors

Gao, P.,Wu, Y.,Patel, D.J. (deposition date: 2013-04-18, release date: 2013-05-15, Last modification date: 2024-02-28)

Primary citation

Gao, P.,Ascano, M.,Wu, Y.,Barchet, W.,Gaffney, B.L.,Zillinger, T.,Serganov, A.A.,Liu, Y.,Jones, R.A.,Hartmann, G.,Tuschl, T.,Patel, D.J.
Cyclic [G(2',5')pA(3',5')p] is the metazoan second messenger produced by DNA-activated cyclic GMP-AMP synthase.
Cell(Cambridge,Mass.), 153:1094-1107, 2013

PubMed Abstract: Recent studies identified cyclic GMP-AMP (cGAMP) as a metazoan second messenger triggering an interferon response. cGAMP is generated from GTP and ATP by cytoplasmic dsDNA sensor cGAMP synthase (cGAS). We combined structural, chemical, biochemical, and cellular assays to demonstrate that this second messenger contains G(2',5')pA and A(3',5')pG phosphodiester linkages, designated c[G(2',5')pA(3',5')p]. We show that, upon dsDNA binding, cGAS is activated through conformational transitions, resulting in formation of a catalytically competent and accessible nucleotide-binding pocket for generation of c[G(2',5')pA(3',5')p]. We demonstrate that cyclization occurs in a stepwise manner through initial generation of 5'-pppG(2',5')pA prior to cyclization to c[G(2',5')pA(3',5')p], with the latter positioned precisely in the catalytic pocket. Mutants of cGAS dsDNA-binding or catalytic pocket residues exhibit reduced or abrogated activity. Our studies have identified c[G(2',5')pA(3',5')p] as a founding member of a family of metazoan 2',5'-containing cyclic heterodinucleotide second messengers distinct from bacterial 3',5' cyclic dinucleotides.

PubMed: 23647843
DOI: 10.1016/j.cell.2013.04.046

Experimental method

X-RAY DIFFRACTION (2 Å)