Transferases;
Transferring phosphorus-containing groups;
Nucleotidyltransferases
BRITE hierarchy

ATP:GTP adenylyltransferase (cyclizing)

ATP + GTP = 2 diphosphate + cyclic Gp(2'-5')Ap(3'-5') (overall reaction) [RN:R10462];
(1a) ATP + GTP = pppGp(2'-5')A + diphosphate;
(1b) pppGp(2'-5')A = cyclic Gp(2'-5')Ap(3'-5') + diphosphate

R10462
Reaction

ATP [CPD:C00002];
GTP [CPD:C00044];
pppGp(2'-5')A

Cyclic Gp(2'-5')Ap(3'-5') is a signalling molecule in mammalian cells that triggers the production of type I interferons and other cytokines.

EC 2.7.7.86 created 2013, modified 2014

1  [PMID:23258413]

Sun L, Wu J, Du F, Chen X, Chen ZJ

Cyclic GMP-AMP synthase is a cytosolic DNA sensor that activates the type I interferon pathway.

Science 339:786-91 (2013)
DOI:10.1126/science.1232458

[hsa:115004] [mmu:214763]

2  [PMID:23722158]

Ablasser A, Goldeck M, Cavlar T, Deimling T, Witte G, Rohl I, Hopfner KP, Ludwig J, Hornung V.

cGAS produces a 2'-5'-linked cyclic dinucleotide second messenger that activates  STING.

Nature 498:380-4 (2013)
DOI:10.1038/nature12306