Table 3.

Variation within functional categories in minimal organisms. Which functional categories show the most variation in fold usage between minimal organisms? The data are calculated as in Table 2, but ignore data from E. coli. The structure-based variation when E coli data are included (from Table 2) is provided for comparison.

Category	Average # of Proteins	Fold-based variation (CVstructure)	Fold-based variation, including E. coli	Sequence-based variation(CVsequence)	Fold-based Rank/Sequence-based Rank
Protein synthesis	95.2	0.108	0.141	0.039	1/1
Transcription	17.6	0.200	0.286	0.199	2/3
All Proteins	606.8	0.210	1.061	0.178	3/2
DNA metabolism	33.0	0.314	0.586	0.328	4/6
Fatty acid and phospholipid metabolism	12.0	0.358	1.328	0.486	5/9
Regulatory functions	7.2	0.402	1.427	0.465	6/8
Purines, pyrimidines, nucleosides, and nucleotides	28.8	0.405	0.462	0.284	7/4
Protein fate	34.6	0.560	0.731	0.303	8/5
Unknown function	27.8	0.776	1.659	0.555	9/12
Transport and binding proteins	27.4	0.796	1.809	0.574	10/13
Energy metabolism	59.4	0.799	1.276	0.454	11/7
Biosynthesis of cofactors, prosthetic groups, and carriers	38.6	0.816	1.332	0.666	12/15
Amino acid biosynthesis	29.0	0.844	0.935	0.782	13/17
Cellular processes	29.8	0.853	1.364	0.636	14/14
Cell envelope	45.8	0.893	1.099	0.506	15/10
Central intermediary metabolism	15.4	0.952	1.228	0.552	16/11
Unclassified	30.0	1.006	2.020	0.749	17/16
Hypothetical proteins	70.6	1.125	1.984	0.871	18/18