BIOINORGANIC CHEMISTRY A Short Course Second Edition

NON-HEME IRON-CONTAINING PROTEINS 457

Figure 7.50 Important amino acid residues surrounding the isocitrate substrate (black
carbon atoms) and the iron – sulfur cluster of aconitase (PDB: 7ACN). Visualized using
The PyMOL Molecular Graphics System and ChemDraw Ultra, version 10.0. (Printed
with permission of Delano Scientifi c, LLC and CambridgeSoft Corporation.) (See color
plate)

arg644

ser642, back

ser643

arg644, front

isocitrate glu262, back

arg452, front

asn446

his167

cys358, back

asn258, back

his147

cys421, front

cys424, front

asp100

his101

gln72

asp165

ser166, back

iron-sulfur cluster

TABLE 7.11 Selected 7ACN Bond Distances (PDB: 7ACN)

Bonding
Atoms

Bond

Length

( Å )

Hydrogen - Bonding

Atoms

Bond

Length

( Å )

Hydrogen - Bonding

Atoms

Bond

Length

( Å )

Fe 1 – S cys358 2.34 Ser642 O γ – O 1ict 3.60 Asp100 O δ 1 – his101
Nδ 1

2.76

Fe 2 – S cys424 2.26 Ser642 O γ – O 6ict 3.41 Asp165 O δ 2 – his147
Nε 2

2.84

Fe 3 – S cys421 2.35 Glu262 O ε 1 – his167
Nε 2

2.80

Fe 4 – O 2ict 2.49
Fe 4 – O 7ict 2.15

ict, isocitrate.