4CUC

Unravelling the multiple functions of the architecturally intricate Streptococcus pneumoniae beta-galactosidase, BgaA.

4CUC の概要

• エントリーDOI: 10.2210/pdb4cuc/pdb
• 関連するPDBエントリー: 4CU6 4CU7 4CU8 4CU9 4CUA 4CUB
• 分子名称: BETA-GALACTOSIDASE, beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, SULFATE ION, ... (5 entities in total)
• 機能のキーワード: hydrolase
• 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: 97874.73

構造登録者

Singh, A.K.,Pluvinage, B.,Higgins, M.A.,Dalia, A.B.,Flynn, M.,Lloyd, A.R.,Weiser, J.N.,Stubbs, K.A.,Boraston, A.B.,King, S.J. (登録日: 2014-03-17, 公開日: 2014-08-20, 最終更新日: 2024-05-08)

主引用文献

Singh, A.K.,Pluvinage, B.,Higgins, M.A.,Dalia, A.B.,Woodiga, S.A.,Flynn, M.,Lloyd, A.R.,Weiser, J.N.,Stubbs, K.A.,Boraston, A.B.,King, S.J.
Unravelling the Multiple Functions of the Architecturally Intricate Streptococcus Pneumoniae Beta-Galactosidase, BgaA.
Plos Pathog., 10:04364-, 2014

PubMed Abstract: Bacterial cell-surface proteins play integral roles in host-pathogen interactions. These proteins are often architecturally and functionally sophisticated and yet few studies of such proteins involved in host-pathogen interactions have defined the domains or modules required for specific functions. Streptococcus pneumoniae (pneumococcus), an opportunistic pathogen that is a leading cause of community acquired pneumonia, otitis media and bacteremia, is decorated with many complex surface proteins. These include β-galactosidase BgaA, which is specific for terminal galactose residues β-1-4 linked to glucose or N-acetylglucosamine and known to play a role in pneumococcal growth, resistance to opsonophagocytic killing, and adherence. This study defines the domains and modules of BgaA that are required for these distinct contributions to pneumococcal pathogenesis. Inhibitors of β-galactosidase activity reduced pneumococcal growth and increased opsonophagocytic killing in a BgaA dependent manner, indicating these functions require BgaA enzymatic activity. In contrast, inhibitors increased pneumococcal adherence suggesting that BgaA bound a substrate of the enzyme through a distinct module or domain. Extensive biochemical, structural and cell based studies revealed two newly identified non-enzymatic carbohydrate-binding modules (CBMs) mediate adherence to the host cell surface displayed lactose or N-acetyllactosamine. This finding is important to pneumococcal biology as it is the first adhesin-carbohydrate receptor pair identified, supporting the widely held belief that initial pneumococcal attachment is to a glycoconjugate. Perhaps more importantly, this is the first demonstration that a CBM within a carbohydrate-active enzyme can mediate adherence to host cells and thus this study identifies a new class of carbohydrate-binding adhesins and extends the paradigm of CBM function. As other bacterial species express surface-associated carbohydrate-active enzymes containing CBMs these findings have broad implications for bacterial adherence. Together, these data illustrate that comprehending the architectural sophistication of surface-attached proteins can increase our understanding of the different mechanisms by which these proteins can contribute to bacterial pathogenesis.

PubMed: 25210925
DOI: 10.1371/JOURNAL.PPAT.1004364

実験手法

X-RAY DIFFRACTION (2.2 Å)