Table 1. GC-content and human-mouse sequence conservation in structural domains of human PK and non-PK genes.

Features	Non- PK genes	PK genes	PK expression level		PK expression breadth
					Ubiqui-tous	Nervous tissue		Testis
			High	Low		Up-reg	Down-reg	Up-reg	Down-reg
5′-spacer
Conservation, %	56.48	55.28	53.62	55.52	55.66	56.59	53.40	58.33	56.60
G+C content, %	45.53	47.39	47.33	47.36	50.65	49.17	49.54	48.05	49.82
Promoter region
Conservation, %	59.97	60.02	58.26	59.63	61.38	61.17	55.96	60.88	60.37
G+C content, %	48.42	50.83	50.25	49.61	56.27	53.19	52.00	48.52	53.10
Primary transcript
Conservation, %	59.88	59.03	59.70	59.28	59.17	58.41	57.78	66.54	61.46
G+C content, %	45.08	45.92	46.65	46.99	49.28	46.92	48.27	46.68	49.65
5′UTR
Conservation, %	72.43	73.54	74.2	70.32	76.61	76.76	68.3	71.66	74.77
G+C content, %	61.27	65.32	66.58	61.01	72.39	64.3	67.12	60.49	67.05
Protein coding regions
Conservation, %	85.28	87.08	87.81	84.85	88.80	88.57	85.03	84.83	87.40
G+C content, %	51.96	52.20	52.53	52.65	54.37	54.05	53.68	51.23	54.25
Introns
Conservation, %	56.14	55.03	55.04	54.77	55.05	55.59	53.44	56.10	57.13
G+C content, %	43.64	45.08	45.82	45.96	48.63	46.53	47.40	40.92	48.97
Intron number	9.3	16.3	17	16.8	13.4	18	14	4.5	14.3
3′UTR
Conservation, %	68.59	69.48	70.83	64.13	71.69	71.19	64.96	66.19	68.47
G+C content, %	42.90	45.20	46.12	46.43	47.39	46.55	46.55	41.44	47.06
3′-spacer
Conservation, %	58.15	58.59	59.52	58.04	57.69	59.87	56.12	56.82	59.40
G+C content, %	44.11	46.44	47.73	46.77	48.87	47.22	48.34	44.33	46.86

Genomic repetitive elements were excluded from computation of sequence conservation. Data are presented as averages. Gene groups are defined in Figure 2 legend.