A glutamyl-tRNA reductase is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are L-glutamate 1-semialdehyde, NADP+, and tRNA(Glu), whereas its 3 products are L-glutamyl-tRNA(Glu), NADPH, and H+. This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-glutamate-semialdehyde: NADP+ oxidoreductase (L-glutamyl-tRNAGlu-forming). This enzyme participates in porphyrin and chlorophyll metabolism.