3B9Z

Crystal structure of the Nitrosomonas europaea Rh protein complexed with carbon dioxide

3B9Z の概要

• エントリーDOI: 10.2210/pdb3b9z/pdb
• 関連するPDBエントリー: 3B9Y
• 分子名称: Ammonium transporter family Rh-like protein, octyl beta-D-glucopyranoside, CARBON DIOXIDE, ... (5 entities in total)
• 機能のキーワード: carbon dioxide, channel, rh protein, co2, transport protein
• 由来する生物種: Nitrosomonas europaea ATCC 19718
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 41412.22

構造登録者

Li, X.,Jayachandran, S.,Nguyen, H.-H.T.,Chan, M.K. (登録日: 2007-11-07, 公開日: 2007-12-18, 最終更新日: 2023-08-30)

主引用文献

Li, X.,Jayachandran, S.,Nguyen, H.H.,Chan, M.K.
Structure of the Nitrosomonas europaea Rh protein.
Proc.Natl.Acad.Sci.Usa, 104:19279-19284, 2007

PubMed Abstract: Amt/MEP/Rh proteins are a family of integral membrane proteins implicated in the transport of NH3, CH(2)NH2, and CO2. Whereas Amt/MEP proteins are agreed to transport ammonia (NH3/NH4+), the primary substrate for Rh proteins has been controversial. Initial studies suggested that Rh proteins also transport ammonia, but more recent evidence suggests that they transport CO2. Here we report the first structure of an Rh family member, the Rh protein from the chemolithoautotrophic ammonia-oxidizing bacterium Nitrosomonas europaea. This Rh protein exhibits a number of similarities to its Amt cousins, including a trimeric oligomeric state, a central pore with an unusual twin-His site in the middle, and a Phe residue that blocks the channel for small-molecule transport. However, there are some significant differences, the most notable being the presence of an additional cytoplasmic C-terminal alpha-helix, an increased number of internal proline residues along the transmembrane helices, and a specific set of residues that appear to link the C-terminal helix to Phe blockage. This latter linkage suggests a mechanism in which binding of a partner protein to the C terminus could regulate channel opening. Another difference is the absence of the extracellular pi-cation binding site conserved in Amt/Mep structures. Instead, CO2 pressurization experiments identify a CO2 binding site near the intracellular exit of the channel whose residues are highly conserved in all Rh proteins, except those belonging to the Rh30 subfamily. The implications of these findings on the functional role of the human Rh antigens are discussed.

PubMed: 18040042
DOI: 10.1073/pnas.0709710104

実験手法

X-RAY DIFFRACTION (1.85 Å)