5EQ2

Crystal Structure of the SrpA Adhesin from Streptococcus sanguinis

Summary for 5EQ2

• Entry DOI: 10.2210/pdb5eq2/pdb
• Related: 5EQ3 5EQ4
• Descriptor: Platelet-binding glycoprotein, CALCIUM ION, ACETATE ION, ... (4 entities in total)
• Functional Keywords: bacterial adhesin, lectin, immunoglobulin fold, serine-rich repeat, sugar binding protein
• Biological source: Streptococcus sanguinis (strain SK36)
• Total number of polymer chains: 2
• Total formula weight: 44843.57

Authors

Loukachevitch, L.V.,McCulloch, K.M.,Vann, K.R.,Wawrzak, Z.,Anderson, S.,Iverson, T.M. (deposition date: 2015-11-12, release date: 2016-01-27, Last modification date: 2024-03-06)

Primary citation

Bensing, B.A.,Loukachevitch, L.V.,McCulloch, K.M.,Yu, H.,Vann, K.R.,Wawrzak, Z.,Anderson, S.,Chen, X.,Sullam, P.M.,Iverson, T.M.
Structural Basis for Sialoglycan Binding by the Streptococcus sanguinis SrpA Adhesin.
J.Biol.Chem., 291:7230-7240, 2016

PubMed Abstract: Streptococcus sanguinisis a leading cause of infective endocarditis, a life-threatening infection of the cardiovascular system. An important interaction in the pathogenesis of infective endocarditis is attachment of the organisms to host platelets.S. sanguinisexpresses a serine-rich repeat adhesin, SrpA, similar in sequence to platelet-binding adhesins associated with increased virulence in this disease. In this study, we determined the first crystal structure of the putative binding region of SrpA (SrpABR) both unliganded and in complex with a synthetic disaccharide ligand at 1.8 and 2.0 Å resolution, respectively. We identified a conserved Thr-Arg motif that orients the sialic acid moiety and is required for binding to platelet monolayers. Furthermore, we propose that sequence insertions in closely related family members contribute to the modulation of structural and functional properties, including the quaternary structure, the tertiary structure, and the ligand-binding site.

PubMed: 26833566
DOI: 10.1074/jbc.M115.701425

Experimental method

X-RAY DIFFRACTION (1.8 Å)