Table 1. Protein∶co-factor and protein tetramerization contacts.
| HmuY∶heme contactsa | Hydrogen bonds and polar interactions and metallo-organic bonds (in Å) | Van-der-Waals interactions performed by protein residues | ||||
| Arg79 Nη2 | Hem301 O1A | 2.81 | Tyr80 | Thr124 | Tyr127 | |
| Tyr80 Oη | Hem301 O2A | 2.59 | Met129 | Met136 | Gly155 | |
| Thr124 Oγ1 | Hem301 O1D | 2.70 | Phe156 | Phe164 | Ala169 | |
| His134 Nε2 | Hem301 FE | 2.04 | Gly170 | Pro171 | Tyr173 | |
| His166 Nε2 | Hem301 FE | 2.09 | Lys204 | |||
| Tyr173 Oη | Hem301 O2A | 2.60 | ||||
a
Atom CBB is the terminal vinyl methylene carbon of pyrrole ring b, and atom CMA is the methyl carbon of pyrrole ring a (see Figure 4D for pyrrole naming within the heme protoporphyrin ring). Atoms O1A, O2A, and O1D are carboxylate oxygens of the propionate substituents of rings a and d, respectively.
b
All the interactions between molecule 1 and molecule 2 are symmetric. Distances 1-2 and 2-1 are given separated by a slash.
c
All the interactions between molecule 1 and molecule 3 are symmetric and made by identical atoms.