| Comments |
P.2 right column 4th paragraph:"The highly ordered, dense nucleosome packaging of DNA presents a substantial chromosome-level cost specific to eukaryotes, although some nucleoid-associated proteins exist and must entail a low level of cost in some bacteria (ref 14). Eukaryotic nucleosomes contain two heterotetrameric histone complexes followed by a linker histone. Throughout eukaryotes, each nucleosome wraps 147 bp, and with an average linker length between nucleosomes of 33 bp, there is on average one nucleosome per 180-bp interval. Weighting by the cost of synthesizing the amino acids that comprise histone proteins and the cost of translating such proteins, the total nucleosome-associated cost is ∼160LgP. The range of variation for this cost among eukaryotes is of minor significance for the types of issues being evaluated here (SI Appendix, Supplementary Table 2)." Lg=gene length Ps=phosphate bonds hydrolyzed. See note above table |