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Crystal structure of the polysialic acid-degrading endosialidase of bacteriophage K1F.
- Source :
-
Nature structural & molecular biology [Nat Struct Mol Biol] 2005 Jan; Vol. 12 (1), pp. 90-6. Date of Electronic Publication: 2004 Dec 19. - Publication Year :
- 2005
-
Abstract
- Phages infecting the polysialic acid (polySia)-encapsulated human pathogen Escherichia coli K1 are equipped with capsule-degrading tailspikes known as endosialidases, which are the only identified enzymes that specifically degrade polySia. As polySia also promotes cellular plasticity and tumor metastasis in vertebrates, endosialidases are widely applied in polySia-related neurosciences and cancer research. Here we report the crystal structures of endosialidase NF and its complex with oligomeric sialic acid. The structure NF, which reveals three distinct domains, indicates that the unique polySia specificity evolved from a combination of structural elements characteristic of exosialidases and bacteriophage tailspike proteins. The endosialidase assembles into a catalytic trimer stabilized by a triple beta-helix. Its active site differs markedly from that of exosialidases, indicating an endosialidase-specific substrate-binding mode and catalytic mechanism. Residues essential for endosialidase activity were identified by structure-based mutational analysis.
- Subjects :
- Bacteriophages genetics
Binding Sites
Crystallography, X-Ray
Escherichia coli genetics
Models, Molecular
Molecular Sequence Data
Mutation genetics
Neuraminidase genetics
Protein Structure, Quaternary
Protein Structure, Tertiary
Bacteriophages enzymology
Escherichia coli enzymology
Neuraminidase chemistry
Neuraminidase metabolism
Sialic Acids metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1545-9993
- Volume :
- 12
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Nature structural & molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 15608653
- Full Text :
- https://doi.org/10.1038/nsmb874