Mapping the energy of superantigen Staphylococcus enterotoxin C3 recognition of an alpha/beta T cell receptor using alanine scanning mutagenesis.

ABSTRACT: Binding of the T cell receptor (TCR) to a bacterial superantigen (SAG) results in stimulation of a large population of T cells and subsequent inflammatory reactions. To define the functional contribution of TCR residues to SAG recognition, binding by 24 single-site alanine substitutions in the TCR Vbeta domain to Staphylococcus aureus enterotoxin (SE) C3 was measured, producing an energy map of the TCR-SAG interaction. The results showed that complementarity determining region 2 (CDR2) of the Vbeta contributed the majority of binding energy, whereas hypervariable region 4 (HV4) and framework region 3 (FR3) contributed a minimal amount of energy. The crystal structure of the Vbeta8.2-SEC3 complex suggests that the CDR2 mutations act by disrupting Vbeta main chain interactions with SEC3, per

SUBMITTER: Churchill HR 

PROVIDER: S-EPMC2195847 | biostudies-literature | 2000 Mar

REPOSITORIES: biostudies-literature