1QYN
Crystal Structure of SecB from Escherichia coli
Summary for 1QYN
| Entry DOI | 10.2210/pdb1qyn/pdb |
| Descriptor | Protein-export protein secB (2 entities in total) |
| Functional Keywords | tetramer, greek key beta sheet, chaperone |
| Biological source | Escherichia coli |
| Total number of polymer chains | 4 |
| Total formula weight | 68404.39 |
| Authors | Dekker, C.,de Kruijff, B.,Gros, P. (deposition date: 2003-09-11, release date: 2003-12-09, Last modification date: 2023-08-23) |
| Primary citation | Dekker, C.,de Kruijff, B.,Gros, P. Crystal structure of SecB from Escherichia coli J.Struct.Biol., 144:313-319, 2003 Cited by PubMed Abstract: The chaperone SecB from Escherichia coli is primarily involved in passing precursor proteins into the Sec system via specific interactions with SecA. The crystal structure of SecB from E. coli has been solved to 2.35 A resolution. The structure shows flexibility in the crossover loop and the helix-connecting loop, regions that have been implicated to be part of the SecB substrate-binding site. Moreover conformational variability of Trp36 is observed as well as different loop conformations for the different monomers. Based on this, we speculate that SecB can regulate the access or extent of its hydrophobic substrate-binding site, by modulating the conformation of the crossover loop and the helix-connecting loop. The structure also clearly explains why the tetrameric equilibrium is shifted towards the dimeric state in the mutant SecBCys76Tyr. The buried cysteine residue is crucial for tight packing, and mutations are likely to disrupt the tetramer formation but not the dimer formation. PubMed: 14643199DOI: 10.1016/j.jsb.2003.09.012 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.35 Å) |
Structure validation
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