Fibronectin receptors from Streptococcus dysgalactiae and Staphylococcus aureus. Involvement of conserved residues in ligand binding.

摘要: The nucleotide sequence of two genes encoding fibronectin (Fn) receptors FnBA and FnBB Streptococcus dysgalactiae S2 revealed the presence repeated motifs (called RA1-A3 RB1-B3, respectively) which encode Fn binding activity (Lindgren, P.-E., McGavin, M. J., Signas, C., Guss, B., Gurusiddappa, S., Hook, M., Lindberg, (1993) Eur. J. Biochem. 214, 819-827). Synthetic peptides 32-37 amino acids, corresponding to individual motifs, were assayed for ability inhibit cells S. dysgalactiae. Within RA peptide A2 was 10-fold more active than either A1 or A3, while in RB only B3 active. same level is observed when these synthetic inhibition Staphylococcus aureus. Likewise, RD1-D3 comprise a ligand domain receptor from aureus, both aureus Assays chemically modified fragments derived chemical proteolytic cleavage suggest that conserved core sequence, defined as ED(T/S) (X9,10)GG(X3,4)(I/V)DF, within 30-amino acid-long segment present RD motifs. Analyses importance residues this indicate motif nonessential, whereas GG (I/V)DF together with additional acidic C-terminal half are required activity.