Table 5.1.

Copy number of cell division and cytoskeleton proteins, determined by Li et al. (2014)

Gene	MOPS complete	MOPS minimal	MOPS complete
			Without methionine
ftsA	984	575	1013
ftsB	487	140	173
ftsE	967	320	649
ftsI	349	144	226
ftsK	508	213	376
ftsL	416	201	423
ftsN	871	269	405
ftsP	905	196	410
ftsQ	336	147	172
ftsW	293	117	169
ftsX	838	244	436
ftsZ	6750	3335	5290
zipA	2128	501	874
minC	857	364	575
minD	5358	2444	3324
minE	3597	1970	2680
matP	601	360	347
slmA	2323	568	952
zapA	2275	738	2008
zapB	34,197	7797	18,090
ZapC/YcbW	155	155	155
ZapD/YacF	1983	373	538
ZapE/YhcM	255	214	262
mreB	11,304	2393	5570
mreC	738	176	333
mreD	367	71	148
rodZ	1309	576	669

This study used ribosome profiling to determine the rate of translation of 95% of the proteins in E. coli. The rates were converted to number of protein molecules synthesized in one cell cycle. Assuming no unusual degradation, the numbers can be taken as the average number of molecules per cell. The E. coli strain MG1655 was grown at 37 °C in three different media with different doubling times: 21.5 and 56.3 min in MOPS complete and incomplete media, and 26.5 min in MOPS complete without methionine. The latter condition required the cell to substantially upregulate the met-E enzyme, altering overall metabolism. We have extracted cell division and cytoskeleton proteins from their table S1. It seems quite valuable to have these numbers determined for all proteins in the identical cell and growth conditions. The 6750 molecules of FtsZ in a cell volume of 2 × 10⁻¹⁵ L is 5.6 μM