TABLE 1.

Activity of the gene rplN for r-protein L14 in E. coli B/r growing at different rates at 37°C

τ (min)	μ (doublings/h)	1012 L14 molecules/OD460 U of cell massa	103 L14 molecules/oriCb	No. of rplN genes/oriCc	103 L14 molecules/rplN genesd	No. of L14 molecules synthesized/min/ rplN genee
100	0.6	6	3	0.90	4	26
60	1.0	7	4	0.85	5	58
40	1.5	8	8	0.82	9	158
30	2.0	10	9	0.80	12	270
24	2.5	11	10	0.79	13	369
20	3.0	13	11	0.77	14	474

^aThe number of L14 molecules in a culture was assumed to be equal to the number of ribosomes present. The number of ribosomes per cell mass was obtained from the total amount of RNA per mass (in RNA nucleotides per OD₄₆₀ unit [Fig. 4b]) by multiplication with 0.84 (84% of total RNA is rRNA) and division by the number of rRNA nucleotides in a 70S ribosome (4,566 [11]). 

^bThe number of L14 molecules per oriC was found from the number of L14 molecules per cell mass above by multiplication with mass per oriC (initiation mass [Fig. 5a]). 

^cThe number of rplN genes per oriC was found from the map location of rplN (at 73 min [1]) and the C period (Fig. 3a), by equations 4 and 6 (Appendix). 

^dThe number of L14 molecules per rplN gene was found by dividing the number of L14 molecules per oriC by the number of rplN genes per oriC. 

^eThe synthesis rate of L14 per rplN gene (in L14 molecules per minute per gene) equals the product of the number of L14 molecules per gene multiplied by the growth rate (ln 2/τ).