4PFU

Crystal structure of mannobiose bound oligopeptide ABC transporter, periplasmic oligopeptide-binding protein (TM1226) from THERMOTOGA MARITIMA at 2.05 A resolution

4PFU の概要

• エントリーDOI: 10.2210/pdb4pfu/pdb
• 関連するPDBエントリー: 4PFT 4PFW 4PFY
• 関連するBIRD辞書のPRD_ID: PRD_900115
• 分子名称: ABC transporter substrate-binding protein, beta-D-mannopyranose-(1-4)-beta-D-mannopyranose, MAGNESIUM ION, ... (5 entities in total)
• 機能のキーワード: oligopeptide abc transporter, periplasmic oligopeptide-binding protein, transport protein
• 由来する生物種: Thermotoga maritima
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 130324.72

構造登録者

Lu, X.,Ghimire-Rijal, S.,Cuneo, M.J. (登録日: 2014-04-30, 公開日: 2014-09-17, 最終更新日: 2023-12-27)

主引用文献

Ghimire-Rijal, S.,Lu, X.,Myles, D.A.,Cuneo, M.J.
Duplication of Genes in an ATP-binding Cassette Transport System Increases Dynamic Range While Maintaining Ligand Specificity.
J.Biol.Chem., 289:30090-30100, 2014

PubMed Abstract: Many bacteria exist in a state of feast or famine where high nutrient availability leads to periods of growth followed by nutrient scarcity and growth stagnation. To adapt to the constantly changing nutrient flux, metabolite acquisition systems must be able to function over a broad range. This, however, creates difficulties as nutrient concentrations vary over many orders of magnitude, requiring metabolite acquisition systems to simultaneously balance ligand specificity and the dynamic range in which a response to a metabolite is elicited. Here we present how a gene duplication of a periplasmic binding protein in a mannose ATP-binding cassette transport system potentially resolves this dilemma through gene functionalization. Determination of ligand binding affinities and specificities of the gene duplicates with fluorescence and circular dichroism demonstrates that although the binding specificity is maintained the Kd values for the same ligand differ over three orders of magnitude. These results suggest that this metabolite acquisition system can transport ligand at both low and high environmental concentrations while preventing saturation with related and less preferentially metabolized compounds. The x-ray crystal structures of the β-mannose-bound proteins help clarify the structural basis of gene functionalization and reveal that affinity and specificity are potentially encoded in different regions of the binding site. These studies suggest a possible functional role and adaptive advantage for the presence of two periplasmic-binding proteins in ATP-binding cassette transport systems and a way bacteria can adapt to varying nutrient flux through functionalization of gene duplicates.

PubMed: 25210043
DOI: 10.1074/jbc.M114.590992

実験手法

X-RAY DIFFRACTION (2.049 Å)