. Author manuscript; available in PMC: 2009 Dec 9.

Published in final edited form as: Biochemistry. 2008 Dec 9;47(49):13074–13083. doi: 10.1021/bi801438g

Table 2.

Fits obtained to the Cu and Se K-EXAFS of hCCS Sec positional variants by curve-fitting using the program EXCURVE 9.2.

	F^a	No^b	R (Å)^c	DW (Å²)	No^b	R (Å)^c	DW (Å²)	No^b	R (Å)^c	DW (Å²)	−E₀
Cu EXAFS
sample		Cu-S			Cu-Se			Cu-Cu
243-CACA	0.310	3.0	2.26	0.009				2.0	2.72	0.012	5.20
243-CAUA	0.129	1.6	2.22	0.004	1.0	2.40	0.007	2.8	2.70	0.012	2.07
243-UACA	0.255	1.8	2.22	0.005	1.0	2.42	0.007	2.3	2.70	0.012	1.91
243-UAUA	0.381	1.1	2.18	0.003	1.9	2.40	0.007	2.6	2.70	0.012	0.40
243-UAUA (no sulfur)	1.454				1.9	2.38	0.007	2.1	2.69	0.012	0.04
Se EXAFS
		Se-C			Se-Cu
243-CAUA	0.285	1.0	1.98	0.010	2.0	2.37	0.007				3.08
243-UACA	0.551	1.0	1.99	0.010	1.9	2.38	0.007				2.92
243-UAUA	0.474	1.0	2.02	0.005	1.9	2.39	0.007				5.37

F is a least-squares fitting parameter defined as $F^{2} = \frac{1}{N} \sum_{i = 1}^{N} k^{6} {(D a t a^{-} M o d e l)}^{2}$

The precision in the estimated coordination numbers is generally considered to be ± 25%

In any one fit, the statistical error in bond-lengths is ±0.005 Å. However, when errors due to imperfect background subtraction, phase-shift calculations, and noise in the data are compounded, the actual error is probably closer to ±0.02 Å.