Recent evidence suggests that the nucleotide-binding oligomerization domain protein 1 (NOD1) has an important role in bacterial recognition and may function as a specific host pattern recognition receptor (PRR) in intracellular compartments. In the June 8 advanced online publication of
Chamaillard et al. performed biochemical and functional analyses using highly purified and synthetic bacterial cell wall peptidoglycan (PGN) compounds. They observed that the core structure recognized by NOD1 is a dipeptide, γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP)—known to exist only in limited number of bacteria (