Ministry of Business, Innovation and Employment (New Zealand)
UOCX1706
ニュージーランド
引用
ジャーナル: Nat Commun / 年: 2023 タイトル: Structure and mechanism of a tripartite ATP-independent periplasmic TRAP transporter. 著者: James S Davies / Michael J Currie / Rachel A North / Mariafrancesca Scalise / Joshua D Wright / Jack M Copping / Daniela M Remus / Ashutosh Gulati / Dustin R Morado / Sam A Jamieson / Michael ...著者: James S Davies / Michael J Currie / Rachel A North / Mariafrancesca Scalise / Joshua D Wright / Jack M Copping / Daniela M Remus / Ashutosh Gulati / Dustin R Morado / Sam A Jamieson / Michael C Newton-Vesty / Gayan S Abeysekera / Subramanian Ramaswamy / Rosmarie Friemann / Soichi Wakatsuki / Jane R Allison / Cesare Indiveri / David Drew / Peter D Mace / Renwick C J Dobson / 要旨: In bacteria and archaea, tripartite ATP-independent periplasmic (TRAP) transporters uptake essential nutrients. TRAP transporters receive their substrates via a secreted soluble substrate-binding ...In bacteria and archaea, tripartite ATP-independent periplasmic (TRAP) transporters uptake essential nutrients. TRAP transporters receive their substrates via a secreted soluble substrate-binding protein. How a sodium ion-driven secondary active transporter is strictly coupled to a substrate-binding protein is poorly understood. Here we report the cryo-EM structure of the sialic acid TRAP transporter SiaQM from Photobacterium profundum at 2.97 Å resolution. SiaM comprises a "transport" domain and a "scaffold" domain, with the transport domain consisting of helical hairpins as seen in the sodium ion-coupled elevator transporter VcINDY. The SiaQ protein forms intimate contacts with SiaM to extend the size of the scaffold domain, suggesting that TRAP transporters may operate as monomers, rather than the typically observed oligomers for elevator-type transporters. We identify the Na and sialic acid binding sites in SiaM and demonstrate a strict dependence on the substrate-binding protein SiaP for uptake. We report the SiaP crystal structure that, together with docking studies, suggest the molecular basis for how sialic acid is delivered to the SiaQM transporter complex. We thus propose a model for substrate transport by TRAP proteins, which we describe herein as an 'elevator-with-an-operator' mechanism.
温度: 293.15 K / 手法: 蒸気拡散法, シッティングドロップ法 詳細: 50 mg/mL protein in 50 mM Tris, pH 8.0, 150 mM sodium chloride, 0.002% w/v L-MNG mixed 1:1 with 0.1 M Bis-Tris, pH 5.0, 2 M ammonium sulfate
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データ収集
回折
平均測定温度: 100 K / Serial crystal experiment: N
放射光源
由来: シンクロトロン / サイト: Australian Synchrotron / ビームライン: MX2 / 波長: 0.95372 Å