Table 1.
The Regions of Factor XII: Structure/Function
| Domains | Amino Acid sequence |
Subdomains of known functional activity |
Proposed Role | Citation |
|---|---|---|---|---|
| Leader peptide | −19-1 | |||
| Fibronectin type II | 1–88 | [6, 20, 64] | ||
| 3–19 | Interaction with FXI |
[12, 13] | ||
| 1–28 | Artificial surface- binding region |
[8, 10, 20] | ||
| 39–47 | HUVEC binding region |
[14] | ||
| 40–44, 78–82 | Zinc-binding sites | [65] | ||
| EGF-like domain | 94–131 | Zinc binding site | [19] | |
| Fibronectin type I | 133–173 | Fibrin and heparin binding |
[7] | |
| 134–153 | Artificial surface binding region |
[10, 26] | ||
| EGF-like domain | 174–210 | Putative artificial surface binding region |
[11, 64] | |
| 174–146 | Putative Zinc binding site |
[19] | ||
| Kringle domain | 215–295 | Putative artificial surface binding region |
[11, 64] | |
| 193–276 | May enhance susceptibility to cleavage by kallikrein |
[66] | ||
| Proline-rich region | 296–349 | [64] | ||
| Catalytic domain | 354–596 | |||
| 353–354 | α-FXIIa fragment formation site |
[5, 20, 64] | ||
| H394, D442, S544 | Catalytic triad of active site |
[5] |