1ABF

SUBSTRATE SPECIFICITY AND AFFINITY OF A PROTEIN MODULATED BY BOUND WATER MOLECULES

1ABF の概要

• エントリーDOI: 10.2210/pdb1abf/pdb
• 分子名称: L-ARABINOSE-BINDING PROTEIN, alpha-D-fucopyranose, beta-D-fucopyranose, ... (4 entities in total)
• 機能のキーワード: 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: 33579.31

構造登録者

Wilson, D.K.,Quiocho, F.A. (登録日: 1992-04-23, 公開日: 1993-10-31, 最終更新日: 2024-02-07)

主引用文献

Quiocho, F.A.,Wilson, D.K.,Vyas, N.K.
Substrate specificity and affinity of a protein modulated by bound water molecules.
Nature, 340:404-407, 1989

PubMed Abstract: Water molecules influence molecular interactions in all biological systems, yet it is extremely difficult to understand their effects in precise atomic detail. Here we present evidence, based on highly refined atomic structures of the complexes of the L-arabinose-binding protein with L-arabinose, D-fucose and D-galactose, that bound water molecules, coupled with localized conformational changes, can govern substrate specificity and affinity. The atoms common to the three sugars are identically positioned in the binding site and the same nine strong hydrogen bonds are formed in all three complexes. Two hydrogen-bonded water molecules in the site contribute further to tight binding of L-arabinose but create an unfavourable interaction with the methyl group of D-fucose. Equally tight binding of D-galactose is attained by the replacement of one of the hydrogen-bonded water molecules by its--CH2OH group, coordinated with localized structural changes which include a shift and redirection of the hydrogen-bonding interactions of the other water molecule. These observations illustrate how ordered water molecules can contribute directly to the properties of proteins by influencing their interaction with ligands.

PubMed: 2818726
DOI: 10.1038/340404a0

実験手法

X-RAY DIFFRACTION (1.9 Å)