Involved in the gluconeogenesis, in growth on fatty acids and is important for initiation of infection in the macrophages. Catalyzes the GTP-dependent conversion of oxaloacetate (OAA) to phosphoenolpyruvate (PEP), the rate-limiting step in the metabolic pathway that produces glucose from lactate and other precursors derived from the citric acid cycle. GTP + oxaloacetate = CO2 + GDP + phosphoenolpyruvate Binds 1 Mn(2+) ion per subunit. Carbohydrate biosynthesis; gluconeogenesis. Monomer. Up-regulated by acetate or palmitate but down-regulated by glucose. Cells lacking this gene show a reduction in the capacity to infect and survive in macrophages. Moreover, mice infected with this mutant are able to reduce the bacterial load much more effectively than mice infected with the parental wild-type bacteria. Belongs to the phosphoenolpyruvate carboxykinase [GTP] family.