Plasma kallikrein (KLKB1) is a 638-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P03952.
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The mean pLDDT of this model is 87.9 (confident overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.
| pLDDT band | Meaning | Share of residues |
|---|---|---|
| Above 90 | Very high: backbone and side chains are usually accurate | 69% |
| 70 to 90 | Confident: backbone generally right | 21% |
| 50 to 70 | Low: treat with caution | 3% |
| Below 50 | Very low: often disordered regions | 7% |
What pLDDT means and how to read it
Participates in the surface-dependent activation of blood coagulation. Activates, in a reciprocal reaction, coagulation factor XII/F12 after binding to negatively charged surfaces. Releases bradykinin from HMW kininogen and may also play a role in the renin-angiotensin system by converting prorenin into renin
Forms a heterodimer with SERPINA5. The zymogen is activated by factor XIIa, which cleaves the molecule into a light chain, which contains the active site, and a heavy chain, which associates with HMW kininogen. These chains are linked by one or more disulfide bonds. Interacts with iripin-3, a serine protease inhibitor from Ixodes ricinus saliva (PubMed:33732248). Interacts with iripin-1, a…
Secreted
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 6I44 | X-ray | 1.36 Å | A=20-638 |
| 2ANY | X-ray | 1.4 Å | A=391-631 |
| 5TJX | X-ray | 1.41 Å | A=376-638 |
| 6T7P | X-ray | 1.42 Å | A=391-632 |
| 5F8Z | X-ray | 1.5 Å | A=391-629 |
| 5F8X | X-ray | 1.55 Å | A=391-629 |
| 10LR | X-ray | 1.58 Å | A=376-638 |
| 10MW | X-ray | 1.62 Å | A=376-638 |
| 10MV | X-ray | 1.66 Å | A=376-638 |
| 6O1S | X-ray | 1.7 Å | E=376-638 |
| 10QS | X-ray | 1.73 Å | A=376-638 |
| 5F8T | X-ray | 1.75 Å | A=391-629 |
| 9VWT | X-ray | 1.77 Å | A=391-627 |
| 10KZ | X-ray | 1.78 Å | A=376-638 |
| 8A3Q | X-ray | 1.8 Å | A=376-638 |
| 2ANW | X-ray | 1.85 Å | A=391-631 |
| 4OGY | X-ray | 2.1 Å | A/B=391-631 |
| 7N7X | X-ray | 2.1 Å | AAA=391-626 |
| 6O1G | X-ray | 2.2 Å | A=1-638 |
| 7QOX | X-ray | 2.32 Å | A/B=20-378 |
Showing 20 of 22 experimental structures (best resolution first).
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