Table 1.

Enzymes encoded in cyanobacterial PST biosynthetic gene clusters. Those highlighted in gray are present in all gene clusters represented.

Enzyme	M. wollei	C. raciborskii	D. circinale	Aphanizomenon sp.	R. brookii	S. crispum	Classification
SxtA	x	x	x	x	x	x	polyketide synthase-like
SxtB	x	x	x	x	x	x	cytidine deaminase
SxtC	x	x		x	x	x	unknown
SxtD	x	x	x	x	x	x	non-heme diiron
SxtE	x	x	x	x	x	x	unknown
SxtF		x			x		“toxic compound extrusion protein”
SxtG	x	x	x	x	x	x	amidinotransferase
SxtH	x	x	x	x	x	x	Rieske oxygenase
SxtI	truncated	x	x	x	x	x	carbamoyltransferase
SxtJ		x	x	x	x	x	unknown
SxtK		x	x	x	x	x	unknown
SxtL		x	x	x	x	x	unknown
SxtM	3 proteins	x	x	x	x	x	export protein
SxtN	2 proteins	x	x	x	x	x	sulfotransferase
SxtO		x	x		x	x	adenylylsulfate kinase
SxtP	x	x	x	x	x	x	regulator/pilli formation
SxtQ	x	x	x	x	x	x	unknown
SxtR	x	x	x	x	x	x	unknown
SxtS	x	x	x	x	x	x	non-heme iron, 2-oxoglutarate dependent
SxtT	x	x	x	x	x	x	Rieske oxygenase
SxtU	x	x	x	x	x	x	NADP+-dependent dehydrogenase
SxtV	x	x	x	x		x	FAD-dependent succinate dehydrogenase
SxtW	x	x		x		x	2[4Fe-4S] ferredoxin
SxtX	x	x		x		x	methyltransferase
SxtY		x					phosphate uptake regulator
SxtZ		x					histidine kinase
GxtA	x				x	x	Rieske oxygenase
SxtACT	x						acyltransferase
SxtSUL	x				x		sulfotransferase