Isolation of cDNA clones for the human complement protein factor B, a class III major histocompatibility complex gene product.

cDNA clones corresponding to a major histocompatibility class III antigen, the complement protein factor B, have been isolated from a human adult liver cDNA library. The clones, ranging in size from 1.0 to 2.3 kilobases, were identified by direct hybridization with two synthetic oligonucleotide mixtures. Two regions of the factor B amino acid sequence, each with minimal ambiguity in codon assignment, were chosen for synthesis of the oligonucleotides. The sequences of two clones have been partially determined. They contain coding information for the amino acid sequence of the Bb fragment of factor B and the entire 3' -untranslated region.