2XD3

The crystal structure of MalX from Streptococcus pneumoniae in complex with maltopentaose.

2XD3 の概要

• エントリーDOI: 10.2210/pdb2xd3/pdb
• 関連するPDBエントリー: 2XD2
• 分子名称: MALTOSE/MALTODEXTRIN-BINDING PROTEIN, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, SULFATE ION, ... (4 entities in total)
• 機能のキーワード: solute-binding protein, sugar binding protein, virulence, alpha-glucan, sugar transport, membrane protein
• 由来する生物種: STREPTOCOCCUS PNEUMONIAE
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 46273.14

構造登録者

Abbott, D.W.,Higgins, M.A.,Hyrnuik, S.,Pluvinage, B.,Lammerts van Bueren, A.,Boraston, A.B. (登録日: 2010-04-28, 公開日: 2010-06-09, 最終更新日: 2023-12-20)

主引用文献

Abbott, D.W.,Higgins, M.A.,Hyrnuik, S.,Pluvinage, B.,Lammerts Van Bueren, A.,Boraston, A.B.
The Molecular Basis of Glycogen Breakdown and Transport in Streptococcus Pneumoniae.
Mol.Microbiol., 77:183-, 2010

PubMed Abstract: The genome of Streptococcus pneumoniae strains, as typified by the TIGR4 strain, contain several genes encoding proteins putatively involved in alpha-glucan degradation, modification and synthesis. The extracellular components comprise an ATP binding cassette-transporter with its solute binding protein, MalX, and the hydrolytic enzyme SpuA. We show that of the commonly occurring exogenous alpha-glucans, S. pneumoniae TIGR4 is only able to grow on glycogen in a MalX- and SpuA-dependent manner. SpuA is able to degrade glycogen into a ladder of alpha-1,4-glucooligosaccharides while the high-affinity interaction (K(a) approximately 10(6) M(-1)) of MalX with maltooligosaccharides plays a key role in promoting the selective uptake of the glycogen degradation products that are produced by SpuA. The X-ray crystallographic analyses of apo- and complexed MalX illuminate the protein's specificity for the degradation products of glycogen and its striking ability to recognize the helical structure of the ligand. Overall, the results of this work provide new structural and functional insight into streptococcal alpha-glucan metabolism while supplying biochemical support for the hypothesis that the substrate of the S. pneumoniaealpha-glucan metabolizing machinery is glycogen, which in a human host is abundant in lung epithelial cells, a common target for invasive S. pneumoniae.

PubMed: 20497336
DOI: 10.1111/J.1365-2958.2010.07199.X

実験手法

X-RAY DIFFRACTION (2 Å)