EC Number   |
Reference |
|---|
   1.14.99.48 | an optical spectroscopic and density functional theory characterization of azide- and cyanide-inhibited wild type and N7A IsdG. Residue Asn7 perturbs the electronic structure of azide-inhibited, but not cyanide-inhibited, IsdG. The terminal amide of Asn7 is a hydrogen bond donor to the alpha-atom of a distal ligand to heme in IsdG. The Asn7-N3 hydrogen bond influences the orientation of a distal azide ligand with respect to the heme substrate. Asn7-N3 hydrogen bond donation causes the azide ligand to rotate about an axis perpendicular to the porphyrin plane and weakens the pi-donor strength of the azide ligand |
740768 |
| 1.14.99.48 | inactive N7A variant of IsdG in complex with Fe3+-protoporphyrin IX, to 1.8 A resolution. The metalloporphyrin is buried into a deep clefts such that the propionic acid forms salt bridges to two Arg residues. His77, a critical residue required for activity, is coordinated to the Fe3+ atom. The bound porphyrin ring forms extensive steric interactions in the binding cleft such that the ring is highly distorted from the plane. This distortion is best described as ruffled and places the beta- and delta-meso carbons proximal to the distal oxygen-binding site. In the IsdG-hemin structure, Fe3+ is pentacoordinate, and the distal side is occluded by the side chain of Ile55 |
725384 |
| 1.14.99.48 | isoform IsdI in complex with cobalt protoporphyrin IX, to 1.8 A resolution. The metalloporphyrin is buried into a deep cleft such that the propionic acid forms salt bridges to two Arg residues. His76, a critical residue required for activity, is coordinated to the Co3+ atom. The bound porphyrin ring forms extensive steric interactions in the binding cleft such that the ring is highly distorted from the plane. This distortion is best described as ruffled and places the beta- and delta-meso carbons proximal to the distal oxygen-binding site. in the structure of IsdI-cobalt protoporphyrin IX, the distal side of the cobalt protoporphyrin IX accommodates a chloride ion in a cavity formed through a conformational change in Ile55. The chloride ion participates in a hydrogen bond to the side chain amide of Asn6 |
725384 |
| 1.14.99.48 | isoform IsdI in complex with heme, heme ruffling and constrained binding of oxygen is consistent with cleavage of the porphyrin ring at the beta- or delta-meso carbon atoms |
725997 |
| 1.14.99.48 | mutant W66Y in complex with heme and its cyanide-bound form. Heme binds to the mutant with less heme ruffling than observed for wild-type IsdI. The reduction potential of the variant (-96 mV versus standard hydrogen electrode) is similar to that of wild-type IsdI (-89 mV) |
740703 |
| 1.14.99.48 | to 1.5 A resolution. Structure of the enzyme resembles the ferredoxin-like fold and forms a beta-barrel at the dimer interface. Two large pockets found on the outside of the barrel contain the putative active sites |
725367 |
