7v4s

Horcolin complex with methyl-alpha-mannose

spinqualitylabelsall models 7v4s, resolution 1.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7v4s is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: MMA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [LECH_HORVU] Mannose-specific lectin. Has a weak agglutinating activity against rabbit erythrocytes (By similarity).[UniProtKB:P82953] Publication Abstract from PubMed Lectins are sugar-binding proteins that have shown considerable promise as antiviral agents because of their ability to interact with envelope glycoproteins present on the surface of viruses such as HIV-1. However, their therapeutic potential has been compromised by their mitogenicity that stimulates uncontrolled division of T-lymphocytes. Horcolin, a member of the jacalin family of lectins, tightly binds the HIV-1 envelope glycoprotein gp120 and neutralizes HIV-1 particles but is nonmitogenic. In this report, we combine X-ray crystallography and NMR spectroscopy to obtain atomic-resolution insights into the structure of horcolin and the molecular basis for its carbohydrate recognition. Each protomer of the horcolin dimer adopts a canonical beta-prism I fold with three Greek key motifs and carries two carbohydrate-binding sites. The carbohydrate molecule binds in a negatively charged pocket and is stabilized by backbone and side chain hydrogen bonds to conserved residues in the ligand-binding loop. NMR titrations reveal a two-site binding mode and equilibrium dissociation constants for the two binding sites determined from two-dimensional (2D) lineshape modeling are 4-fold different. Single-binding-site variants of horcolin confirm the dichotomy in binding sites and suggest that there is allosteric communication between the two sites. An analysis of the horcolin structure shows a network of hydrogen bonds linking the two carbohydrate-binding sites directly and through a secondary binding site, and this coupling between the two sites is expected to assume importance in the interaction of horcolin with high-mannose glycans found on viral envelope glycoproteins. Structure and Carbohydrate Recognition by the Nonmitogenic Lectin Horcolin.,Narayanan V, Bobbili KB, Sivaji N, Jayaprakash NG, Suguna K, Surolia A, Sekhar A Biochemistry. 2022 Feb 28. doi: 10.1021/acs.biochem.1c00778. PMID:35225598 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA