4IKX
Crystal structure of peptide transporter POT (E310Q mutant)
4IKX の概要
エントリーDOI | 10.2210/pdb4ikx/pdb |
関連するPDBエントリー | 4IKV 4IKW 4IKY 4IKZ |
分子名称 | Di-tripeptide ABC transporter (Permease), SULFATE ION, OLEIC ACID, ... (4 entities in total) |
機能のキーワード | major facilitator superfamily, transport protein |
由来する生物種 | Geobacillus kaustophilus |
タンパク質・核酸の鎖数 | 1 |
化学式量合計 | 55432.37 |
構造登録者 | |
主引用文献 | Doki, S.,Kato, H.E.,Solcan, N.,Iwaki, M.,Koyama, M.,Hattori, M.,Iwase, N.,Tsukazaki, T.,Sugita, Y.,Kandori, H.,Newstead, S.,Ishitani, R.,Nureki, O. Structural basis for dynamic mechanism of proton-coupled symport by the peptide transporter POT. Proc.Natl.Acad.Sci.USA, 110:11343-11348, 2013 Cited by PubMed Abstract: Proton-dependent oligopeptide transporters (POTs) are major facilitator superfamily (MFS) proteins that mediate the uptake of peptides and peptide-like molecules, using the inwardly directed H(+) gradient across the membrane. The human POT family transporter peptide transporter 1 is present in the brush border membrane of the small intestine and is involved in the uptake of nutrient peptides and drug molecules such as β-lactam antibiotics. Although previous studies have provided insight into the overall structure of the POT family transporters, the question of how transport is coupled to both peptide and H(+) binding remains unanswered. Here we report the high-resolution crystal structures of a bacterial POT family transporter, including its complex with a dipeptide analog, alafosfalin. These structures revealed the key mechanistic and functional roles for a conserved glutamate residue (Glu310) in the peptide binding site. Integrated structural, biochemical, and computational analyses suggested a mechanism for H(+)-coupled peptide symport in which protonated Glu310 first binds the carboxyl group of the peptide substrate. The deprotonation of Glu310 in the inward open state triggers the release of the bound peptide toward the intracellular space and salt bridge formation between Glu310 and Arg43 to induce the state transition to the occluded conformation. PubMed: 23798427DOI: 10.1073/pnas.1301079110 主引用文献が同じPDBエントリー |
実験手法 | X-RAY DIFFRACTION (2.3 Å) |
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