T-Cell Receptor Beta (TCRb)

TCRB locus was the longest contiguous stretch of DNA analyzed to that time in humans. A portion of the TCRB locus has been duplicated and translocated from chromosome 7 to chromosome 9, which suggested a possible mechanism for the creation of new multigene families. At least 30% of the TCRB locus is composed of genomewide interspersed repeats, but these do not appear to facilitate the duplication of locus-specific repeats. Eight locus-specific repeats (homology units) have duplicated in a tandem or dispersed manner.specific germline-encoded amino acids in the TCR promote 'generic' MHC recognition and control thymic selection. In mice expressing single, rearranged TCR beta-chains, individual mutation of amino acids in the complementarity-determining region 2-beta to ala reduced development of the entire TCR repertoire.