TABLE 2.

Novel two-component signaling systems of S. pseudopneumoniae

TCS	RRa	HKb	Species of closest homologue	Family of regulators	Associated gene category
14	SPPN_RS00570	SPPN_RS00565	S. mitis	LytTR	Bacteriocins
15	SPPN_RS11635	SPPN_RS01890	S. mitis	YesN	Ferric iron transport
16	SPPN_RS03570	SPPN_RS03565	S. pseudoporcinus, S. canis	OmpR	Potassium transportc
17	SPPN_RS07705	SPPN_RS07700	S. parasanguinis	LytTR/YesN	Thiamine biosynthesisd
18	E3V59_10390	E3V59_10385	S. mitis	YesN/AraC	Sugar transport
19	E3V34_05540	E3V34_05535	S. suis	CitB	Bacitracin export

^aLocus tag of the response regulator (RR). Locus tag in IS7493 was used when present.

^bLocus tag of the sensor histidine kinase (HK). Locus tag in IS7493 was used when present.

^cSimilar to KdpD/KdpE from E. coli (61).

^dSimilar to TCS02 of S. thermophilus (62).