Function
Preprotein translocase (PPT) is responsible for the recognition and membrane translocation of preproteins. PPT contains receptors and import motor[1]. The translocase pathway contains:
- SecB - a chaperone protein[2]
- SecY, SecE, SecG or Sec61 an integral membrane complex
- SecD, SecF - proteins promoting the release of the mature peptide into the periplasm
- SecA - an ATPase unit[3].
For more details see SecA PBD motions.
3D structures of preprotein translocase
Preprotein translocase 3D structures
Updated on 07-May-2025
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- Preprotein translocase SecY + SecE + SecA
- 6itc – BsPPT SecA + SecY + SecE + nanobody + GFP + translocating peptide – Bacillus subtilis – Cryo EM
- Preprotein translocase SecY + SecE + SecB
- 1rh5, 1rhz – MjPPT SecY + SecE + SecB – Methanocaldococcus jannaschii
- Preprotein translocase SecY + SecE + SecG
- 2akh, 2aki – EcPPT SecY + SecE + SecG – Escherichia coli - CryoEM
- 2yxq, 2yxr – MjPPT SecY + SecE + SecG
- 3dkn – PPT SecY + SecE + SecG + RNA – dog - CryoEM
- 3bo0, 3bo1 – EcPPT SecY + SecE + SecG + 23S ribosomal RNA - CryoEM
- 4v7i, 3j45, 3j46 – EcPPT SecY + SecE + SecG + large ribosomal subunit - CryoEM
- 4v4n – MjPPT SecY + SecE + SecG + large ribosomal subunit - CryoEM
- Preprotein translocase SecY + SecG
- 6r7l – EcPPT SecY + SecG - CryoEM
- Preprotein translocase SecY + SecE
- 3mp7 – PPT SecY + SecE – Pyrococcus furiosus
- 2zjs – TtPPT SecY + SecE + antibody – Thermus thermophilus
- 2zqp – TtPPT SecY + SecE
- 4v6m – EcPPT SecY + SecE + large ribosomal subunit - CryoEM
- 5abb – EcPPT SecY + SecE + green-light absorbing proteorhodopsin - CryoEM
- Preprotein translocase SecY + SecE + SecG + SecA
- 3din – TmPPT SecY + SecE + SecG + SecA – Thermotoga maritima
- 3dl8 – PPT SecY + SecE + SecA + SecG – Aquifex aeolicus - CryoEM
- Preprotein translocase SecY + SecE + SecG + SecD + SecF
- 5mg3 – EcPPT SecY + SecE + SecG + SecD + SecF + YIDC - CryoEM
- Preprotein translocase SecA
- 1m6n, 1tf5, 2ibm – BsPPT SecA – Bacillus subtilis
- 3iqm, 3iqy – BsPPT SecA (mutant)
- 1tm6 – EcPPT SecA C terminal - NMR
- 2ipc – TtPPT SecA
- 3jux – TmPPT SecA
- 2fsf – EcPPT SecA
- 2fsf – EcPPT SecA
- 3bxz – EcPPT SecA dead motor domains (mutant)
- 1nl3 – MtPPT SecA – Mycobacterium tuberculosis
- Preprotein translocase SecA complex
- 1m74, 1tf2 – BsPPT SecA + Mg + ADP
- 1ozb – PPT SecA C terminal + SecB - Haemophilus influenzae
- 2fsh – EcPPT SecA + AMPPNP
- 2fsi – EcPPT SecA + ADP
- 2fsg – EcPPT SecA + ATP
- 2vda – EcPPT SecA + maltoporin signal peptide - NMR
- 3jv2 – BsPPT SecA + peptide
- 5eul – BsPPT SecA + SecE + SecY + AYC08
- 1nkt – MtPPT SecA + ADP
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References
- ↑ Economou A. Bacterial preprotein translocase: mechanism and conformational dynamics of a processive enzyme. Mol Microbiol. 1998 Feb;27(3):511-8. PMID:9489663
- ↑ Fekkes P, de Wit JG, van der Wolk JP, Kimsey HH, Kumamoto CA, Driessen AJ. Preprotein transfer to the Escherichia coli translocase requires the co-operative binding of SecB and the signal sequence to SecA. Mol Microbiol. 1998 Sep;29(5):1179-90. PMID:9767586
- ↑ Schmidt MG, Kiser KB. SecA: the ubiquitous component of preprotein translocase in prokaryotes. Microbes Infect. 1999 Oct;1(12):993-1004. PMID:10617931
