Tropomyosin-like seven residue periodicity in three immunologically distinct streptococal M proteins and its implications for the antiphagocytic property of the molecule
| Autor: | V A Fischetti, B N Manjula |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
chemistry.chemical_classification
Protein Conformation Streptococcus pyogenes Structural similarity Immunology Hydrogen Bonding Articles Tropomyosin Biology Peptide Fragments Protein tertiary structure Homology (biology) Amino acid Structure-Activity Relationship Protein structure Bacterial Proteins Phagocytosis chemistry Biochemistry Immunology and Allergy Amino Acid Sequence Peptide sequence Protein secondary structure |
| Zdroj: | The Journal of Experimental Medicine |
| ISSN: | 1540-9538 0022-1007 |
| DOI: | 10.1084/jem.151.3.695 |
| Popis: | Partial sequences of three immunologically distinct group A streptococcal M proteins (M5, M6, and M24) revealed significant homology with each other, certain amino acid residues being conserved within the three molecules. In addition, a common feature of the sequenced regions of these M proteins was their high alpha-helical potential and the presence of a repeating seven residue periodicity that is characteristic of the double helical coiled-coil molecule, tropomyosin. The existence of a tropomyosin-like seven residue periodicity strongly suggests that regions of these three M proteins may participate in intra- and/or intermolecular coiled-coil interactions. Because of the constraints imposed by such a repeating periodicity, certain conserved residues within the M proteins would occupy spatially equivalent positions in the tertiary structure of these molecules. This common characteristic could play an important role in the common antiphagocytic property of the immunologically diverse M molecules. In addition to similarities in the secondary structure of M proteins and tropomyosin, significant sequence homology has also been observed between certain regions of these molecules with up to 50% identical residues. As a result of the striking structural similarity with tropomyosin, M proteins may play a regulatory role in the contractile mechanisms involved in phagocytosis. |
| Databáze: | OpenAIRE |
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