Table 3.

Sequence Analysis of Putative Promoters

All	Total	% Total	Strict TATA		Less strict TATA
			obs	exp	obs	exp
25%–45% GC	1462	14.2	1023	1218.80	1450	1460.90
45%–65% GC	6318	61.5	1577	1442.20	4535	4078.50
65%–85% GC	2496	24.3	219	63.9	640	246
10276	100	2819	2725	6625	5785
Experimental	Total	% Total	Strict TATA		Less strict TATA
			obs	exp	obs	exp
25%–45% GC	13	8.6	9	10.7	12	13
45%–65% GC	119	78.3	26	29.5	75	81
65%–85% GC	20	13.2	2	0.75	5	2.9
	152	100	37	40.95	92	96.9

We grouped the putative promoters in the entire dataset of 10,276 and, separately, the 152 experimental promoters into three classes: 25%–45%, 45%–65%, and 65%–85% GC. The number of promoters in each class are shown. Based on the nucleotide frequency within each group, we also calculated the expected number of promoter fragments in which a strict TATA-box (TATA[T/A][T/A]) or a less-strict TATA-box (TA[T/A][T/A][T/A][T/A]) would appear at least once by chance. Then we calculated the number of promoter fragments in both our experimental and total dataset in which these elements appeared at least once. The shaded boxes indicate those cases in which the observed and expected frequencies of TATA elements are significantly different from one another (P < 0.05).