5K9T
SecA-N68, a C-terminal truncation of the SecA ATPase from E. coli
Summary for 5K9T
| Entry DOI | 10.2210/pdb5k9t/pdb |
| Descriptor | Protein translocase subunit SecA, ADENOSINE-5'-DIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total) |
| Functional Keywords | preprotein translocase, seca-n68, atpase, c-terminal truncation, n-terminus, peptide binding, protein transport |
| Biological source | Escherichia coli (strain 55989 / EAEC) |
| Cellular location | Cell inner membrane ; Peripheral membrane protein ; Cytoplasmic side : B7LFW8 |
| Total number of polymer chains | 1 |
| Total formula weight | 64738.35 |
| Authors | Shilton, B.H.,Vezina, G.C. (deposition date: 2016-06-01, release date: 2017-06-07, Last modification date: 2023-09-27) |
| Primary citation | Yazdi, A.K.,Vezina, G.C.,Shilton, B.H. An alternate mode of oligomerization for E. coli SecA. Sci Rep, 7:11747-11747, 2017 Cited by PubMed Abstract: SecA is the ATPase of preprotein translocase. SecA is a dimer in solution and changes in its oligomeric state may function in preprotein translocation. The SecA-N68 construct, in which the C-terminal helical domains of SecA are deleted, was used to investigate the mechanism of SecA oligomerization. SecA-N68 is in equilibrium between monomers, dimers, and tetramers. Subunit interactions in the SecA-N68 tetramer are mediated entirely by unstructured regions at its N- and C-termini: when the termini are deleted to yield SecA-N68∆NC, the construct is completely monomeric. This monomeric construct yielded crystals diffracting to 2.6 Å that were used to solve the structure of SecA-N68, including the "preprotein crosslinking domain" (PPXD) that was missing from previous E. coli SecA structures. The SecA-N68 structure was combined with small angle X-ray scattering (SAXS) data to construct a model of the SecA-N68 tetramer that is consistent with the essential roles of the extreme N- and C-termini in oligomerization. This mode of oligomerization, which depends on binding of the extreme N-terminus to the DEAD motor domains, NBD1 and NBD2, was used to model a novel parallel and flexible SecA solution dimer that agrees well with SAXS data. PubMed: 28924213DOI: 10.1038/s41598-017-11648-5 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.6 Å) |
Structure validation
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