Table 1 SCOP fold classes of the 125 heme binding protein chains in the non-redundant dataset

a.104

9

Cytochrome P450

a.1

14

Globin-like

a.123

1

Nuclear receptor ligand-binding domain

a.126

1

Serum albumin-like

a.132

2

Heme oxygenase-like

a.138

8

Multiheme cytochromes

a.24

2

Four-helical up-and-down bundle

a.266

2

Indolic compounds 2,3-dioxygenase-like

a.3

9

Cytochrome c

a.39

1

EF Hand-like

a.45

1

GST C-terminal domain-like

a.93

5

Heme-dependent peroxidases

b.1

4

Immunoglobulin-like beta-sandwich

b.2

1

Common fold of diphtheria toxin/transcription factors...

b.60

2

Lipocalins

b.66

1

4-bladed beta-propeller

b.82

1

Double-stranded beta-helix

c.150

1

EreA/ChaN-like

c.47

1

Thioredoxin fold

c.79

1

Tryptophan synthase β subunit-like PLP-dependent enzymes

c.92

1

Chelatase-like

d.110

1

Profilin-like

d.120

1

Cytochrome b5-like heme/steroid binding domain

d.151

1

DNase I-like

d.174

1

Nitric oxide (NO) synthase oxygenase domain

d.278

2

Ligand-binding domain in NO signalling & Golgi transport

d.58

3

Ferredoxin-like

e.5

2

Heme-dependent catalase-like

e.62

1

Heme iron utilization protein-like

f.21

5

Heme-binding four-helical bundle

f.24

1

Cytochrome c oxidase subunit I-like

Total: 31

86