. Author manuscript; available in PMC: 2008 Mar 7.

Published in final edited form as: Biochemistry. 2007 Mar 23;46(16):4876–4887. doi: 10.1021/bi061651w

Table 3.

Distances between the Closest Carbon Atoms of the Tyrosine and Nucleotide Rings^a

	residue number	R_DA (Å)^b	E^c
Tyr residues surrounding the DNA binding saddle	94	11.7	0.82
	139	12.8	0.72
	185	10.4	0.90
	195	13.4	0.66
“out of the saddle” Tyr residues	224	15.7	0.43
	231	18.0	0.25

The positions of tyrosines in the TBPc structure are shown in Figure 10.

Donor–acceptor distance.

The effectiveness of Tyr–DNA energy migration (E) was calculated with the equation 1/E = 1 + (R_DA/R_o)⁶, where R_o ≈ 15 Å for the tyrosine–DNA FRET donor–acceptor pair.