TABLE 1.
Heme and porphyrin affinities for S. aureus HemQ and other heme-binding proteins
| Protein, organism | Ligand (method used) | Kd | pH | Ref. |
|---|---|---|---|---|
| nm | ||||
| HemQ S. aureus | Heme (UV-visible) | 720 (0.21) | 6.8 | This work |
| Heme (fluorescence) | 1680 (160) | 6.8 | ||
| Protoporphyrin IX (fluorescence) | 2210 (100) | 6.8 | ||
| HemQ M. tuberculosis | Heme (UV-visible) | 3–4 × 104 | 8.0 | 15 |
| YfeX E. coli | Heme | 3.9 (1.6) | 8.0 | 41 |
| Protoporphyrin IX | 4.8 (2.8) | 8.0 | ||
| EfeB E. coli | Heme to apo-EfeB (ITC)a | 29.6 (4.3) | 8.0 | 41 |
| Heme to PPIX-EfeB (ITC) | 214 (50) | 8.0 | ||
| BtDyp Bacteroides theatiotaomicron | Heme (ITC) | 158 | 7.6 | 43 |
| TyrA Shewanella oneidensis | Heme (ITC) | 50 | 7.6 | |
| IsdC S. aureus | Heme (UV-visible) | 340 (120) | 6.0 | 44 |
| IsdG S. aureus | Heme (UV-visible) | 5,000 (1,500) | 7.5 | 14 |
| PhuS P. aeruginosa | Heme (Fluorescence) | 180 (10) | 7.8 | 29 |
| Myoglobin sperm whale | Heme (UV, CD, fluorescence) | 0.88 × 10−4 | 7.0 | 73 |
a ITC is isothermal titration calorimetry.