Table 2.

Examples of bacteria capable of de novo folate synthesis and of genes that are still missing

	De novo early steps						De novo signature enzymes		De novo late steps					PABA synthesis
Organism	GCYH-I		DHNTPase		DHNA		DHPS	HPPK	DHFS		DHFR			PabAabc
	FolE	FolE2	FolQ	FolQ2*	FolB	FolB2*	FolP	FolK	FolC	FolC2	FolA	FolM	Dhfr2
Escherichia coli K12	+	-	?	?	+	+	+	+	+	-	+	+	-	+
Staphylococcus aureus	-	+	?	?	+	+	+	+	+	-	+	-	-	+
Chlamydia trachomatis	?	?	?	?	+	+	+	+	-	+	+	-	-	?
Lactococcus lactis	+	-	+	-	+	+	+	+	+		+	-	-	?
Parachlamydia sp. UWE25	+		+#	-	+#	+	+	+	+	-	-	+	-	+
Helicobacter pylori	+	-	?	?	+	+	+#	+	+	-	-	-	+#	+
Prochlorococcus marinus	+	-	?	?	+	+	+	+	+	-	?	?	?	+
Clostridium perfringens	+	-	-	+	+	+	+	+	+	-	+	-	-	+
Rickettsia felis	+	-	?	?	?	?	+	+	+	-	+	-	-	?
Geobacter metallireducens	-	+	?	?	-	+	+	+	+	-	+	-	-	+
Mycobacterium leprae	+	-	?	?	+	+	FolP1	+	+	-	+	-	-	+
							FolP2
Shewanella denitrificans	+	-	?	?	+	+	+	FolK1	+		+	+	-	+
								FolK2
Xylella fastidiosa	+	+	?	?	+	-	+	FolK1	+	-	+	+	-	+
								FolK2

* Prediction not experimentally verified; ^# Fused proteins; Underlined and bold: physical clustering; (+): gene identified; (-): no identified gene; (?): predicted missing gene.