TABLE 2.

Loss of biological pathways in Pneumocystis

Category	Type of loss	Biological pathway or component affected
Stress responses	Loss of many transcription factors	pH sensing
		Osmotic stress response
		Oxidative stress response
		Cell wall stress response
Protein synthesis	Loss of de novo synthesis	All 20 amino acids
Carbohydrate metabolism	Loss of pathway	Gluconeogenesis
		Glyoxylate cycle
		Fermentation
Lipid metabolism	Loss of synthesis	Ergosterol
		Cholesterol
		myo-Inositol
		Choline
		Ether lipids
		Complex sphingolipids
		Phosphatidylinositol
		Phosphatidylcholine
		Glycerol
	Loss of function	Fatty acid β-oxidation
Cofactor metabolism	Loss of synthesis	Coenzyme A
		Thiamine
		Biotin
		Siderophores
		Reductive iron uptake
	Loss of enzyme	Carbonic anhydrase