Table 3.

Phylogenetic comparison of Na⁺ ion cycle members^a

Chlamydia trachomatis gene	p/P Trp ratio	“Ca. Protochlamydia amoebophila”		Escherichia coli
		Gene	p/P Trp ratio	Gene	p/P Trp ratio
Primary Na+ pump genes
CT278	2.08	PC0301	1.73	b1630	2.43
CT279	1.66	PC0300	1.14
CT280	1.47	PC0299	0.83	b1632	0.85
CT281	2.15	PC0298	1.79	b1627	0.68
CT634b	0.22	PC0095	0.19
CT740	1.95	PC1533	1.33	b3844	0.84
Primary H+ pump genes
CT013	3.54	PC1630	2.66	b0978	2.30
CT014	2.08	PC1629	1.71	b0979	2.95
Na+-specific A1A0-type ATPase genes
CT303	3.07	PC1659	1.50
CT304	0	PC1676	0.63
CT305	0.81	PC1677	1.66
CT306	0.52	PC1678	0.41
CT307	0.72	PC1679	0.60
CT308	1.24	PC1680	0.89
CT309	2.37	PC1681	1.01
CT310	1.01	PC1682	0
Na+/H+ antiporter gene
CT857	2.50
Na+-dependent transporter genes
CT409	1.16	PC1598	1.17	b0007	1.93
CT435	1.15	PC0622	1.35
CT401	0.51	PC1785	0.42	b4077	0.90
CT230	0.76	PC1734	0.84
CT204	3.39			b0770	2.20
CT554	1.27	PC0767	0.22	b0401	1.20
CT231	3.43	PC1260	2.84

^aValues in bold indicate high p/P Trp ratios.

^bThe CT634 gene is a target of the iron-responsive regulator encoded by dcrA at the CT296 locus (but see discussion of possible uncertainties in “Regulation by Chlamydial DcrA” in the text). DcrA has a very high Trp content (p/P Trp ratio = 2.72).