2YIP

Crystal Structure of Parasite Sarcocystis muris Microneme Protein SML- 2 in complex with 1-Thio-beta-D-Galactose (SPACEGROUP P212121)

Summary for 2YIP

• Entry DOI: 10.2210/pdb2yip/pdb
• Related: 2YIL 2YIO
• Descriptor: MICRONEME ANTIGEN L2, 1-thio-beta-D-galactopyranose, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: sugar binding protein, apple-domain tandem repeat, pan_ap, pan_1, galactose-binding lectin, cellular adhesion, micronemal protein
• Biological source: SARCOCYSTIS MURIS
• Total number of polymer chains: 6
• Total formula weight: 92846.90

Authors

Mueller, J.J.,Heinemann, U. (deposition date: 2011-05-16, release date: 2011-11-02, Last modification date: 2024-10-16)

Primary citation

Mueller, J.J.,Weiss, M.S.,Heinemann, U.
Pan-Modular Structure of Microneme Protein Sml-2 from Parasite Sarcocystis Muris at 1.95 A Resolution and its Complex with 1-Thio-Beta-D-Galactose.
Acta Crystallogr.,Sect.D, D67:936-, 2011

PubMed Abstract: The microneme protein SML-2 is a member of a small family of galactose-specific lectins that play a role during host-cell invasion by the apicomplexan parasite Sarcocystis muris. The structures of apo SML-2 and the 1-thio-β-D-galactose-SML-2 complex were determined at 1.95 and 2.1 Å resolution, respectively, by sulfur-SAD phasing. Highly elongated dimers are formed by PAN-domain tandems in the protomer, bearing the galactose-binding cavities at the distal apple-like domains. The detailed structure of the binding site in SML-2 explains the high specificity of galactose-endgroup binding and the broader specificity of the related Toxoplasma gondii protein TgMIC4 towards galactose and glucose. A large buried surface of highly hydrophobic character and 24 intersubunit hydrogen bonds stabilize the dimers and half of the 12 disulfides per dimer are shielded from the solvent by the polypeptide chain, thereby enhancing the resistance of the parasite protein towards unfolding and proteolysis that allows it to survive within the intestinal tracts of the intermediate and final hosts.

PubMed: 22101820
DOI: 10.1107/S0907444911037796

Experimental method

X-RAY DIFFRACTION (2.14 Å)