1U77

Crystal Structure of Ammonia Channel AmtB from E. Coli

1U77 の概要

• エントリーDOI: 10.2210/pdb1u77/pdb
• 分子名称: Probable ammonium transporter (2 entities in total)
• 機能のキーワード: right handed helical bundle, transmembrane helices, membrane channel, ammonia channel, transport protein
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell inner membrane; Multi-pass membrane protein: P69681
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 40434.96

構造登録者

Khademi, S.,O'Connell III, J.,Remis, J.,Robles-Colmenares, Y.,Miercke, L.J.W.,Stroud, R.M. (登録日: 2004-08-02, 公開日: 2004-09-21, 最終更新日: 2024-10-09)

主引用文献

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

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: 15361618
DOI: 10.1126/science.1101952

実験手法

X-RAY DIFFRACTION (2 Å)