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| Identifier |
000334471 |
| Title |
Μοριακή ανάλυση της αλληλεπίδρασης του DEAD κινητήρα της SecA με την προπρωτεϊνη |
| Alternative Title |
Determinants for preprotein cross-talk with the dead motor of SecA |
| Creator |
Χατζή, Κατερίνα
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Thesis advisor
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Οικονόμου, Αναστάσιος
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| Abstract |
SecA is the motor subunit of the bacterial protein translocase nanomachine. During preprotein translocation SecA undergoes controlled cycles of ATP hydrolysis accompanied by domain movements that are expected to lead to preprotein translocation. SecA is formed by the DEAD motor and two specialization domains, the Preprotein Binding Domain (PBD) and the C-domain. The DEAD motor is formed by two subdomains, the Nucleotide Binding Domain (NBD) and the IRA2. The PBD contacts the helicase DEAD motor through a narrow Stem that packs tightly against helix α8 of the NBD. The α8 helix- Stem interaction is the only part of the protein were the PBD is in physical contact with the DEAD motor.
In order to understand the role of the α8 helix for SecA and the importance of its interaction with the Stem for the preproteins translocation, single point mutations were introduced at the α8 helix. Five out of the seven mutated derivatives had reduced functionality compared to the SecA. One out of the mutated derivatives, that it is expected to loosen the a8-stem interaction, it had in the absence of a preproprein the biochemical phenotype that SecA has when it is translocating preproteins. It was recently determined that the preprotein signal peptide attaches to SecA at a site in the immediate vicinity of the α8 helix-Stem interface. Clearly Stem-DEAD motor interaction is critical for translocase activity. We propose that preproteins control the SecA motor by regulating the α8-Stem interaction.
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| Physical description |
59 σ. : εικ. ; 30 εκ. |
| Language |
Greek |
| Issue date |
2008-12-04 |
| Collection
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School/Department--School of Sciences and Engineering--Department of Biology--Post-graduate theses
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Type of Work--Post-graduate theses
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| Notes |
Διατμηματικό Μεταπτυχιακό Πρόγραμμα "Πρωτείνικής Βιοτεχνολογίας" |
| Views |
220 |
Μοριακή ανάλυση της αλληλεπίδρασης του DEAD κινητήρα της SecA με την προπρωτεϊνη
