Functionally Significant Mobile Regions of Escherichia coli SecA ATPase Identified by NMR
| Autor: | Joanna F. Swain, Lila M. Gierasch, Yi-Te Chou |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Models
Molecular Signal peptide Magnetic Resonance Spectroscopy Protein Conformation ATPase Molecular Sequence Data Chromosomal translocation Sequence (biology) Biology medicine.disease_cause environment and public health Biochemistry Bacterial Proteins Escherichia coli medicine Amino Acid Sequence Molecular Biology Adenosine Triphosphatases SecA Proteins Escherichia coli Proteins Genetic Variation Membrane Transport Proteins Cell Biology Peptide Fragments Recombinant Proteins Cytoplasm biology.protein Biophysics bacteria Dimerization SEC Translocation Channels |
| Zdroj: | Journal of Biological Chemistry. 277:50985-50990 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m209237200 |
| Popis: | SecA, a 204-kDa homodimeric protein, is a major component of the cellular machinery that mediates the translocation of proteins across the Escherichia coli plasma membrane. SecA promotes translocation by nucleotide-modulated insertion and deinsertion into the cytoplasmic membrane once bound to both the signal sequence and portions of the mature domain of the preprotein. SecA is proposed to undergo major conformational changes during translocation. These conformational changes are accompanied by major rearrangements of SecA structural domains. To understand the interdomain rearrangements, we have examined SecA by NMR and identified regions that display narrow resonances indicating high mobility. The mobile regions of SecA have been assigned to a sequence from the second of two domains with nucleotide-binding folds (NBF-II; residues 564-579) and to the extreme C-terminal segment of SecA (residues 864-901), both of which are essential for preprotein translocation activity. Interactions with ligands suggest that the mobile regions are involved in functionally critical regulatory steps in SecA. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|