Table 2.

The strength of selected codon usage bias (S) in HE genes, for each AA in M. maripaludis and E. coli. Only AAs with twofold or fourfold degeneracy, and only those for which both species exhibit preference for an optimal codon (shown), are included.

twofold degenerate AAs					fourfold degenerate AAs
	M. maripaludis		E. coli			M. maripaludis		E. coli
AA	codon	S	codon	S	AA	codon	S	codon	S
Phe	UUC	1.79	UUC	1.79	Pro	CCU	0.55	CCG	0.79
Tyr	UAC	2.27	UAC	1.39	Thr	ACA	0.61	ACU	1.52
His	CAC	1.28	CAC	1.16	Val	GUU	0.28	GUU	1.14
Asn	AAC	2.12	AAC	1.74	Ala	GCU	0.95	GCU	1.49
Asp	GAC	0.58	GAC	1.17	Gly	GGU	0.61	GGU	1.21