1U77
Crystal Structure of Ammonia Channel AmtB from E. Coli
Summary for 1U77
| Entry DOI | 10.2210/pdb1u77/pdb |
| Descriptor | Probable ammonium transporter (2 entities in total) |
| Functional Keywords | right handed helical bundle, transmembrane helices, membrane channel, ammonia channel, transport protein |
| Biological source | Escherichia coli |
| Cellular location | Cell inner membrane; Multi-pass membrane protein: P69681 |
| Total number of polymer chains | 1 |
| Total formula weight | 40434.96 |
| Authors | Khademi, S.,O'Connell III, J.,Remis, J.,Robles-Colmenares, Y.,Miercke, L.J.W.,Stroud, R.M. (deposition date: 2004-08-02, release date: 2004-09-21, Last modification date: 2024-10-09) |
| Primary citation | Khademi, S.,O'Connell III, J.,Remis, J.,Robles-Colmenares, Y.,Miercke, L.J.W.,Stroud, R.M. Mechanism of ammonia transport by Amt/MEP/Rh: structure of AmtB at 1.35 A Science, 305:1587-1594, 2004 Cited by PubMed Abstract: The first structure of an ammonia channel from the Amt/MEP/Rh protein superfamily, determined to 1.35 angstrom resolution, shows it to be a channel that spans the membrane 11 times. Two structurally similar halves span the membrane with opposite polarity. Structures with and without ammonia or methyl ammonia show a vestibule that recruits NH4+/NH3, a binding site for NH4+, and a 20 angstrom-long hydrophobic channel that lowers the NH4+ pKa to below 6 and conducts NH3. Favorable interactions for NH3 are seen within the channel and use conserved histidines. Reconstitution of AmtB into vesicles shows that AmtB conducts uncharged NH3. PubMed: 15361618DOI: 10.1126/science.1101952 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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