Signal recognition particle 43 kDa protein, chloroplastic (CAO) is a 373-residue protein from Arabidopsis thaliana. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: O22265.
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The mean pLDDT of this model is 79.0 (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 | 46% |
| 70 to 90 | Confident: backbone generally right | 31% |
| 50 to 70 | Low: treat with caution | 5% |
| Below 50 | Very low: often disordered regions | 19% |
What pLDDT means and how to read it
Component of the chloroplast signal recognition particle pathway. Required for post-translational targeting of proteins into the thylakoid membrane but seems to be dispensable for co-translational targeting with a translating ribosome present. May be able to function independently of cpFTSY and FFC/cpSRP54 in targeting LHCPs to the thylakoids. Acts as a highly specific chaperone for LHCPs, preventing aggregation and being able to dissolve aggregates
Homodimer. Component of the cpSRP complex, composed of a FFC/cpSRP54 monomer and a CAO/cpSRP43 dimer. Interacts (via chromo domains 2 and 3) with ALB3 (via C-terminus), but not with ALB3L1/ALB4. Can interact simultaneously with ALB3 and FFC/cpSRP54. Interacts with LHCP and LTD
Plastid, chloroplast stroma
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 3DEO | X-ray | 1.5 Å | A=85-267 |
| 3DEP | X-ray | 2.7 Å | A=85-267 |
| 5E4X | X-ray | 2.75 Å | A=319-368 |
| 5E4W | X-ray | 2.8 Å | C/D=265-369 |
| 3UI2 | X-ray | 3.18 Å | A=84-327 |
| 1X32 | NMR | A=84-128 | |
| 1X3P | NMR | A=320-373 | |
| 1X3Q | NMR | A=265-319 | |
| 2HUG | NMR | A=265-319 | |
| 2N88 | NMR | A=316-373 |
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