TauD enzyme system

One of our goals for studying TauD was to correlate our spectroscopic results with the structural information available from the X ray crystal structure of the ternary complex prepared under anaerobic conditions. Subsequently, this information could be used as a foundation to study similarities in catalytic mechanisms between different members of this enzyme class. Because the catalytic mechanism involves the displacement of bound water molecules from the Fe(II) cofactor, we studied samples of Fe(II)NO-TauD without cosubstrates and with just the aKG added to determine if FIYSCORE could be used to follow this chemistry. Figure 16(a) shows the FIYSCORE spectrum at g = 4.00 for Fe(II)NO TauD in aqueous buffer without the two cosubstrates. Two water molecules should be coordinated to the Fe(II)NO center under these conditions. The HYSCORE shows a weak, disordered system of overlapping H arcs for this sample, which most likely reflects a high degree of... 

---