Involved in glutamate biosynthesis. 2 L-glutamate + NAD(+) = 2-oxoglutarate + H(+) + L-glutamine + NADH Binds 1 [3Fe-4S] cluster. Amino-acid biosynthesis; L-glutamate biosynthesis via GLT pathway; L-glutamate from 2-oxoglutarate and L-glutamine (NAD(+) route): step 1/1. Energy metabolism; nitrogen metabolism. Monomer. Expressed in leaf blades and sheaths. Belongs to the glutamate synthase family. Was originally thought to correspond to two different genes. Was originally thought to correspond to two different genes.