prokaryotic wts for promoters 
-35 region:
P -50-49-48-47-46-45-44-43-42-41-40-39-38-37-36-35-34-33-32-31-30-29-28-27-26
  107109109110110110110110110111111110111112112112112112112112112112112112112
T  41 33 32 25 34 22 35 35 42 27 32 42 47 14 92 94 11 19 15 37 46 34 38 48 34
C  22 27 18 29 20 14 20 12 22 23 16 25 10 43  7  6 11 18 60  8 25 23 23 17 20
A  28 38 30 37 35 56 42 42 37 42 39 18 25 26  2  6  2 72 26 50 26 34 25 26 31
G  16 11 29 19 21 18 13 21  9 19 24 26 29 29 11  6 88  3 11 17 15 21 26 21 27
-10 region:
P -23-22-21-20-19-18-17-16-15-14-13-12-11-10 -9 -8 -7 -6 -5
  112112112112112112112112112112112112112112112112112112112
T  35 28 28 27 39 51 34 43 26 31 89  3 49 15 19108 31 29 21
C  34 21 24 27 12 25 20 25 20 27 10  2 16 14 22  3 13 16 30
A  20 39 33 33 39 23 29 16 23 19  2106 29 66 57  1 35 23 31
G  23 24 27 25 22 13 29 28 43 35 11  1 18 17 14  0 33 24 30
+ region:
P -2 -1  1  2  3  4  5  6  7  8  9 10
  86 88 88 88 88 88 88 88 88 88 88 88
T 16 22  2 42 27 23 20 25 27 15 16 29
C 29 49  4 25 25 13 18 22 17 17 16 17
A 20  9 45 16 24 25 28 24 24 32 35 26
G 21  8 37  5 12 27 22 17 20 24 21 16
Notes:
D. K. and McClure, R., nar 11 2237-2255 (1983)

E. coli promoters have been shown to contain 2 regions of conserved sequence
located about 10 and 35 bases upstream of the transcription startsite. These
are TATAAT and TTGACA with an allowed spacing of 15 to 21 bases between. The
spacing with maximum efficiency was 17 bases and all but 12 of the 112 
sequences could be aligned with a separation of 17 +or-1 bases. The standard
promoter has spacing 7 and 17 bases between the startsite and the -10 region,
and the -10 and -35 regions, respectively. The spacing between the -10 region
and the startsite is usually 6 or 7 bases but varies between 4 and 8 bases.
There is an AT rich region of 8 to 10 bases upstream of the -35 region.
Iniation with a purine is highly prefered with G being used if A is not
present.
Gap penalties:
	15 0.02   (only exists as mutant)
	16 0.2
	17 1.0
	18 0.2
	19 0.05   (guess)
	20 0.02   (guess)
	21 0.01   (guess)
Two processes in volved: 1) recognition
			 2) melting (needs recognition for initiation
				     and then AT richness)

factor of about 1 order of magnitude difference for all AT against all GC
in terms of activity.
Andrew Travers says there are upstream regions that resemble -35 and -10
regions (on both strands).