ALPK1 (Alpha Kinase 1) is an atypical serine/threonine-protein kinase that specifically detects and binds the pathogen-associated pattern metabolites (PAMPs), ADP-beta-D-manno-heptose (Beta-ADP-Heptose) or D-glycero-beta-D-manno-heptose 1,7-bisphosphate (HBP). These metabolic precursors of lipopolysaccharide (LPS) biosynthesis are present in all Gram-negative and some Gram-positive bacteria.  This interaction stimulates ALPK1 to phosphorylate and activate TIFA, initiating an innate immune response