Oxidoreductases;
Acting on the CH-NH2 group of donors;
With NAD+ or NADP+ as acceptor
BRITE hierarchy

L-glutamate:NADP+ oxidoreductase (transaminating)

2 L-glutamate + NADP+ = L-glutamine + 2-oxoglutarate + NADPH + H+ (overall reaction) [RN:R00114];
(1a) L-glutamate + NH3 = L-glutamine + H2O [RN:R00256];
(1b) L-glutamate + NADP+ + H2O = NH3 + 2-oxoglutarate + NADPH + H+ [RN:R00248]

R00114 R00248 R00256
Reaction

L-glutamate [CPD:C00025];
NADP+ [CPD:C00006];
NH3 [CPD:C00014];
H2O [CPD:C00001]

Binds FMN, FAD, 2 [4Fe-4S] clusters and 1 [3Fe-4S] cluster. The reaction takes place in the direction of L-glutamate production. The protein is composed of two subunits, alpha and beta. The alpha subunit is composed of two domains, one hydrolysing L-glutamine to NH3 and L-glutamate (cf. EC 3.5.1.2, glutaminase), the other combining the produced NH3 with 2-oxoglutarate to produce a second molecule of L-glutamate (cf. EC 1.4.1.4, glutamate dehydrogenase [NADP+]). The beta subunit transfers electrons from the cosubstrate. The NH3 is channeled within the alpha subunit through a 31 A channel. The chanelling is very efficient and in the intact alpha-beta complex ammonia is produced only within the complex. In the absence of the beta subunit, coupling between the two domains of the alpha subunit is compromised and some ammonium can leak.

EC 1.4.1.13 created 1972 as EC 2.6.1.53, transferred 1976 to EC 1.4.1.13, modified 2001, modified 2012