Reaction: ATP + GTP = AMP + guanosine 3'-diphosphate 5'-triphosphate
Other name(s): stringent factor; guanosine 3',5'-polyphosphate synthase; GTP pyrophosphokinase; ATP-GTP 3'-diphosphotransferase; guanosine 5',3'-polyphosphate synthetase; (p)ppGpp synthetase I; (p)ppGpp synthetase II; guanosine pentaphosphate synthetase; GPSI; GPSII
Systematic name: ATP:GTP 3'-diphosphotransferase
Comments: GDP can also act as acceptor.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 63690-89-1
References:
1. Fehr, S. and Richter, D. Stringent response of Bacillus stearothermophilus: evidence for the existence of two distinct guanosine 3',5'-polyphosphate synthetases. J. Bacteriol. 145 (1981) 68-73. [PMID: 6161916]
2. Sy, J. and Akers, H. Purification and properties of guanosine 5',3'-polyphosphate synthetase from Bacillus brevis. Biochemistry 15 (1976) 4399-4403. [PMID: 184817]