Enolase (Anaplasma marginale) (Eno)

Enolase (Eno) of Anaplasma marginale is a primary example of a moonlighting protein, a class of proteins that perform multiple, unrelated biological functions depending on their cellular location. In the cytoplasm, it acts as a central glycolytic enzyme that catalyzes the dehydration of 2-phospho-D-glycerate to phosphoenolpyruvate (PMID: 28410041). When exported to the bacterial surface, it functions as an adhesin that facilitates the attachment of A. marginale to bovine erythrocytes and tick vector cells, and it binds host plasminogen to assist in the degradation of extracellular barriers (PMID: 32306352). Other A. marginale proteins, such as Elongation Factor Tu (EF-Tu), also exhibit similar moonlighting properties, contributing to the pathogen's ability to infect and persist within its ruminant hosts (PMID: 30129737). Because of its critical role in pathogenesis and its accessibility on the cell exterior, Enolase is a major focus for the development of recombinant subunit vaccines against bovine anaplasmosis. No small-molecule drugs are currently approved to specifically target this protein, and the infection is typically managed using broad-spectrum antibiotics like oxytetracycline.

Other names

Anaplasma marginale moonlighting protein2-phospho-D-glycerate hydro-lyasePhosphopyruvate hydrataseAmEnoSurface-localized enolase

Induction of protective immunity via vaccination to block surface-localized bacterial adhesion to host cells; potential competitive inhibition of plasminogen binding to prevent tissue invasion.