(S)-4-amino-5-oxopentanoate = 5-aminolevulinate Porphyrin-containing compound metabolism; protoporphyrin-IX biosynthesis; 5-aminolevulinate from L-glutamyl-tRNA(Glu): step 2/2. Porphyrin-containing compound metabolism; chlorophyll biosynthesis. Homodimer. Belongs to the class-III pyridoxal-phosphate-dependent aminotransferase family. HemL subfamily.