2WD6

Crystal structure of the Variable Domain of the Streptococcus gordonii Surface Protein SspB

2WD6 の概要

• エントリーDOI: 10.2210/pdb2wd6/pdb
• 分子名称: AGGLUTININ RECEPTOR, CALCIUM ION, GLYCEROL, ... (5 entities in total)
• 機能のキーワード: cell adhesion, secreted, v-region, cell wall, ag i/ii protein, surface adhesin, peptidoglycan-anchor
• 由来する生物種: STREPTOCOCCUS GORDONII
• 細胞内の位置: Secreted, cell wall ; Peptidoglycan-anchor : P16952
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 77540.68

構造登録者

Forsgren, N.,Persson, K. (登録日: 2009-03-20, 公開日: 2009-07-28, 最終更新日: 2024-05-08)

主引用文献

Forsgren, N.,Lamont, R.J.,Persson, K.
Crystal Structure of the Variable Domain of the Streptococcus Gordonii Surface Protein Sspb.
Protein Sci., 18:1896-, 2009

PubMed Abstract: The Antigen I/II (AgI/II) family of proteins are cell wall anchored adhesins expressed on the surface of oral streptococci. The AgI/II proteins interact with molecules on other bacteria, on the surface of host cells, and with salivary proteins. Streptococcus gordonii is a commensal bacterium, and one of the primary colonizers that initiate the formation of the oral biofilm. S. gordonii expresses two AgI/II proteins, SspA and SspB that are closely related. One of the domains of SspB, called the variable (V-) domain, is significantly different from corresponding domains in SspA and all other AgI/II proteins. As a first step to elucidate the differences among these proteins, we have determined the crystal structure of the V-domain from S. gordonii SspB at 2.3 A resolution. The domain comprises a beta-supersandwich with a putative binding cleft stabilized by a metal ion. The overall structure of the SspB V-domain is similar to the previously reported V-domain of the Streptococcus mutans protein SpaP, despite their low sequence similarity. In spite of the conserved architecture of the binding cleft, the cavity is significantly smaller in SspB, which may provide clues about the difference in ligand specificity. We also verified that the metal in the binding cleft is a calcium ion, in concurrence with previous biological data. It was previously suggested that AgI/II V-domains are carbohydrate binding. However, we tested that hypothesis by screening the SspB V-domain for binding to over 400 glycoconjucates and found that the domain does not interact with any of the carbohydrates.

PubMed: 19609934
DOI: 10.1002/PRO.200

実験手法

X-RAY DIFFRACTION (2.3 Å)