1GUB

Hinge-bending motion of D-allose binding protein from Escherichia coli: three open conformations

1GUB の概要

• エントリーDOI: 10.2210/pdb1gub/pdb
• 関連するPDBエントリー: 1GUD 1RPJ
• 分子名称: D-ALLOSE-BINDING PERIPLASMIC PROTEIN, NICKEL (II) ION (3 entities in total)
• 機能のキーワード: sugar-binding protein, periplasmic binding protein, allose, hinge bending, conformational change, sugar binding protein
• 由来する生物種: ESCHERICHIA COLI
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 30476.50

構造登録者

Magnusson, U.,Chaudhuri, B.N.,Ko, J.,Park, C.,Jones, T.A.,Mowbray, S.L. (登録日: 2002-01-24, 公開日: 2003-03-06, 最終更新日: 2023-12-13)

主引用文献

Chaudhuri, B.N.,Ko, J.,Park, C.,Jones, T.A.,Mowbray, S.L.
Structure of D-Allose Binding Protein from Escherichia Coli Bound to D-Allose at 1.8 A Resolution
J.Mol.Biol., 286:1519-, 1999

PubMed Abstract: ABC transport systems for import or export of nutrients and other substances across the cell membrane are widely distributed in nature. In most bacterial systems, a periplasmic component is the primary determinant of specificity of the transport complex as a whole. We report here the crystal structure of the periplasmic binding protein for the allose system (ALBP) from Escherichia coli, solved at 1.8 A resolution using the molecular replacement method. As in the other members of the family (especially the ribose binding protein, RBP, with which it shares 35 % sequence homology), this structure consists of two similar domains joined by a three-stranded hinge region. The protein is believed to exist in a dynamic equilibrium of closed and open conformations in solution which is an important part of its function. In the closed ligand-bound form observed here, D-allose is buried at the domain interface. Only the beta-anomer of allopyranose is seen in the crystal structure, although the alpha-anomer can potentially bind with a similar affinity. Details of the ligand-binding cleft reveal the features that determine substrate specificity. Extensive hydrogen bonding as well as hydrophobic interactions are found to be important. Altogether ten residues from both the domains form 14 hydrogen bonds with the sugar. In addition, three aromatic rings, one from each domain with faces parallel to the plane of the sugar ring and a third perpendicular, make up a hydrophobic stacking surface for the ring hydrogen atoms. Our results indicate that the aromatic rings forming the sugar binding cleft can sterically block the binding of any hexose epimer except D-allose, 6-deoxy-allose or 3-deoxy-glucose; the latter two are expected to bind with reduced affinity, due to the loss of some hydrogen bonds. The pyranose form of the pentose, D-ribose, can also fit into the ALBP binding cleft, although with lower binding affinity. Thus, ALBP can function as a low affinity transporter for D-ribose. The significance of these results is discussed in the context of the function of allose and ribose transport systems.

PubMed: 10064713
DOI: 10.1006/JMBI.1999.2571

実験手法

X-RAY DIFFRACTION (3.1 Å)