MnSOD from E. coliPDB structure 1VEW

Gln 145 Trp 168Tyr 34

Thr 33 His 30 His 170

OHCu

Azide bound to MnSOD from E. coli PDB structure 1MNG

N3¯

Structure of Active site of MnSOD from E. coliFree and bound to Azide (N3¯)

The bound N3¯ anion suggests how O2¯ approaches the active site.

Azide bound to FeSOD from E. coli PDB structure 1ISB

Azide bound to MnSOD from E. coli PDB structure 1MNG

N3¯

Orientation of azide differs in structures of Fe- and MnSOD from E. coli

Azide chanes orientation in Fe structure, raises question about active site flexibility.

MnSOD from E. coli

His 170

OH

Cu

FeSOD from M. tuberculosisPDB structure 1IDS

Gln 145His 145

The active site of FeSOD from M. tuberculosis is very similar to that of MnSOD from E. coli

Similarity of structures suggests that inhibitors of E coli MnSOD could be used against M. tuberculosis.

Comparison of CuZnSOD active sties with and without azide

Azide complexed Bovine CuZnSOD Human CuZnSOD PDB 1SXZ PDB 1PU0

Glu 133

Lys 136

Pro 62

Gly 139

Arg 141

Ser 140

Glu 133

Lys 136

Pro 62

Asn 139