cGMP-dependent protein kinase from Toxoplasma gondii: functional expression in E. coli and molecular characterization

Background The apicomplexan parasite Toxoplasma gondii is an obligate intracellular human pathogen causing toxoplasmosis predominantly in immune-compromised hosts such as cancer and transplant patients as well as patients with AIDS [1]. A specific cGMP-dependent protein kinase (TgPKG) which appears to be crucial for host invasion has been identified in T. gondii and related coccidial protozoa [2]. However, detailed structural and biochemical analyses have been hampered due to the inability to functionally express these kinases in high yields in systems other than their parasite host organisms.