GCN2 is a stress response kinase that phosphorylates the translation initiation factor eIF2to inhibit general protein synthesis when activated by uncharged tRNA and stalled ribosomes. The presence of a HisRS-like domain in GCN2, normally associated with the ability to bind and aminoacylate tRNAs, led to the hypothesis that eIF2 kinase activity is regulated by the direct binding of this domain to uncharged tRNA. Here we solved the structure of the HisRS-like domain in the context of full-length GCN2 by cryoEM. Structure and function analysis shows the HisRS-like domain of GCN2 has lost tRNA charging, ATP binding, and histidine binding activity but retains the ability to bind tRNA. Hydrogen deuterium exchange mass spectrometry (HX-MS), site-directed mutagenesis and computational docking experiments support a tRNA binding model that overlaps with but is partially shifted from that employed by bona fide HisRS enzymes. These results demonstrate that the HisRS-like domain of GCN2 is a pseudoenzyme and advance our understanding of GCN2 regulation and function.