Involved in regulation of glucose metabolism. Transcriptional repressor of the gap-1 gene and of the edd-glk-gltR-2 and zwf-pgl-eda operons. Acts by binding directly to an inverted pseudopalindromic sequence in the promoter region. Binding of 2-keto-3-deoxy-6-phosphogluconate (KDPG) to HexR releases the repressor from its target sequences. Monomer in solution. Binds DNA as a dimer.