APRT GI:71773201 adenine phosphoribosyltransferase isoform b 1 madselqlve qrirsfpdfp tpgvvfrdis pvlkdpasfr aaigllarhl 50 51 kathggridy iagldsrgfl fgpslaqelg lgcvlirkrg klpgptlwas 100 101 ysleygkael eiqkdalepg qrvvvvddll atgv