Pathway · 3 proteins
Damaged-protein turnover
Proteases and associated ATPases contribute to protein removal.
How it works
- HslU/HslV, Clp-associated ATPases, FtsH, DegQ and HtpX annotations identify several proteolytic systems in different cellular contexts.
- ATP-dependent systems couple substrate recognition and chain handling to proteolysis; other proteases act through different access and activation mechanisms. Cleavage produces fragments for further recycling.
- These are alternative or complementary disposal routes rather than a universal sequence. A list of protease families does not establish substrate preference, localization or the measured fate of a damaged protein.
Grouped by the atlas’s curated pathway map. The table order is not a proven reaction order.
Its proteins
| Protein | EC | Reaction (UniProt) | Metal or cluster | Amino acids | Certainty |
|---|---|---|---|---|---|
| Protease HtpX homolog | 3.4.24.- | — | Zn(2+) | 302 | Step named |
| ATP-dependent zinc metalloprotease FtsH | 3.4.24.- | — | Zn(2+) | 634 | Step named |
| Periplasmic serine protease | — | — | — | 453 | Step named |
Also part of this pathway
These proteins are described under another pathway, but also take part here.
| Protein | EC | Reaction (UniProt) | Metal or cluster | Amino acids | Certainty |
|---|---|---|---|---|---|
| ATP-dependent Clp proteaseHome: Protein turnover | — | — | — | 810 | System only |
| ATP-dependent Clp protease ATP-binding subunit ClpXHome: Protein turnover | — | — | Zn(2+) | 412 | Step named |
| ATP-dependent protease ATPase subunit HslUHome: Protein turnover | — | — | — | 450 | Step named |
| ATP-dependent protease subunit HslVHome: Protein turnover | 3.4.25.2 | ATP-dependent cleavage of peptide bonds with broad specificity. | Na(+) | 176 | Step named |
Origins
How would the first cell have dealt with damaged proteins?
The books searched discuss the handling of damaged and misfolded proteins only in present-day cells.
Recognising a damaged protein means telling it apart from a working one. Today this is done by proteins that are themselves products of the system they protect.
From the books: Alberts et al., Molecular Biology of the Cell, p. 718.
The wider question for this part of the cell: origins for surviving oxygen damage.
Sources
- Atlas pathway grouping from the VF5 reference-genome system map (Deckert et al. 1998; Braakman & Smith 2014)
Other pathways in this group: Peroxide and superoxide handling · Not yet placed in a pathway