Table 4.

Comparison between various amino acid indices and secondary structural traits of six sets of proteins of Prochlorococcus and non-Prochlorococcus orthologs

Organisms		Mean of amino acid indices				Secondary structural traits (%)
		Hydrophobicity	Aromaticity	pI	Instability Index	Alpha helix	Beta sheet	Coil
Set I (303 pairs)	BC	-0.14	0.08	6.51	34.34	38.62	16.64	44.74
	LL1	-0.08	0.06	6.61	38.72	38.07	14.33	47.60
	LL3	-0.13	0.07	7.09	37.33	36.37	15.22	48.41
	HL3	-0.17	0.07	7.23	36.17	34.65	16.01	49.35
Set II (136 pairs)	EC	-0.05	0.08	6.91	36.58	40.26	14.43	45.31
	LL1	-0.07	0.07	6.57	38.94	37.44	14.76	47.80
	LL3	-0.12	0.07	7.13	37.65	35.59	16.17	48.24
	HL3	-0.15	0.08	7.30	35.63	33.87	16.63	49.49
Set III (265 pairs)	FT	-0.15	0.08	7.30	33.68	38.22	16.60	45.19
	LL1	-0.12	0.06	6.64	39.46	37.71	14.35	47.94
	LL3	-0.17	0.07	7.18	37.93	36.03	15.12	48.85
	HL3	-0.21	0.07	7.33	36.57	34.56	15.79	49.64
Set IV (175 pairs)	SN	-0.03	0.07	6.88	41.23	40.46	13.39	46.14
	LL1	-0.06	0.06	6.61	39.39	37.54	14.27	48.19
	LL3	-0.10	0.07	7.15	37.82	35.47	15.13	49.40
	HL3	-0.15	0.08	7.25	35.96	34.25	15.73	50.01
Set V (963 pairs)	SSP	-0.09	0.08	6.41	38.77	37.72	14.60	47.68
	LL1	-0.06	0.07	6.76	42.06	38.80	13.15	48.05
	LL3	-0.11	0.08	7.45	38.95	36.00	14.81	49.18
	HL3	-0.16	0.09	7.81	36.21	34.34	16.12	49.55
Set VI (961 pairs)	NOS	-0.08	0.08	6.58	38.59	38.35	15.05	46.61
	LL1	-0.06	0.07	6.81	41.96	39.00	13.11	47.89
	LL3	-0.11	0.08	7.49	38.87	36.25	14.74	49.01
	HL3	-0.17	0.09	7.82	36.30	34.27	16.09	49.62

BC - Bacillus cereus (35.5% G+C), EC - Escherichia coli (50.8% G+C), FT - Francisella tularensis (32.3% G+C), SN - Synechococcus elongatus (55.5% G+C), SSP - Synechocystis sp. (47.4% G+C), NOS - Nostoc sp. (41.3% G+C)