by using oligonucleotide-directed mutagenesis , we have produced a point mutation ( guanine to adenine ) at nucleotide 388 of the gene for human beta-adrenergic receptor ( beta ar ) that results in a substitution of asparagine for the highly conserved aspartic acid at position 130 in the putative third transmembrane domain of the human beta ar ( [ asn130 ] beta ar ) .
C1519623
transmembrane
C0001643
beta ar