. Author manuscript; available in PMC: 2014 Sep 17.

Published in final edited form as: Biochemistry. 2013 Sep 5;52(37):10.1021/bi400965u. doi: 10.1021/bi400965u

Table 1.

Heme Coordination and Spectral Features of Wild-type and Mutant HtsA Proteins

Protein^a	Known/proposed axial ligand(s)	Absorption Peaks			Major MCD Features
Protein^a	Known/proposed axial ligand(s)	Soret (nm)	ε mM⁻¹ cm⁻¹	Visible (nm)	Soret (nm)	Δε/H (M cm T)⁻¹	Visible (nm)	Δε/H (M cm T)⁻¹
Shp	Met/Met	420	116	529	410	44.8	550	2.7
				560	417	0	554	0
					424	−50.9	564	−7.8
ShpM66A (pH 9.0)	Met	404	120	486	403	17.3	583	4.6
				528	412	0	601	0
				604	418	−12.3	618	−9.2
ShpM66A (pH8.0)	Met and Met/H₂O^a	406	128	490	403	26.1	592	3.7
				526	411	0	603	0
				601	419	−18.6	620	−6.7
ShpM66A (pH 6.0)	Met/H₂O	408	157	502	403	34.2	620	−1.3
				624	410	0	627	−2.1
					417	−26	632	−3.5
ShpM153	Met	402	100	480^b	401	6.4	588	5.2
				598	409	0	607	0
					418	−6.3	624	−7.4
^c HtsA	Met/His	412	123	532	407	38	557	1.9
				562^b	416	0	564	0
					423	−45	578	−5.6
^c HtsA^M79A	His/H₂O	403	187	498	399	20	548	−1.5
				536^b	407	0	580	−2
				630	414	−16.5	643	−3.3
^c HtsA^H229A	Met	402	114	482	404	11	589	4.9
				524	410	0	608	0
				600	419	−7.5	624	−7.2

All spectra were measured at pH 8.0 unless specified.

Estimated from shoulders.

Data for HtsA proteins are from Ref. 28.