Ligases;
Forming carbon-nitrogen bonds;
Carbon-nitrogen ligases with glutamine as amido-N-donor

xanthosine-5'-phosphate:L-glutamine amido-ligase (AMP-forming)

ATP + XMP + L-glutamine + H2O = AMP + diphosphate + GMP + L-glutamate (overall reaction) [RN:R01231];
(1a) L-glutamine + H2O = L-glutamate + NH3 [RN:R00256];
(1b) ATP + XMP + NH3 = AMP + diphosphate + GMP [RN:R01230]

R00256 R01230 R01231;
(other) R08244

ATP [CPD:C00002];
XMP [CPD:C00655];
L-glutamine [CPD:C00064];
H2O [CPD:C00001];
NH3 [CPD:C00014]

Involved in the de novo biosynthesis of guanosine nucleotides. An N-terminal glutaminase domain binds L-glutamine and generates ammonia, which is transferred by a substrate-protective tunnel to the ATP-pyrophosphatase domain. The enzyme can catalyse the second reaction alone in the presence of ammonia.

EC 6.3.5.2 created 1961, modified 2013