Restriction digests of the clone give the following sizes (kb): BamHI--3.05, 1.9; SalI--4.9; HindIII--4.9; ClaI--4.9; EcoRI--4.9. The cDNA insert can be released using the flanking BamHI sites from the SV40 sequences in the vector. The insert contains HindII, EcoRI, and PstI (2) sites. The HindII/PstI fragment encoding the transmembrane segment is sufficiently divergent to distinguish between mdr1 and mdr3. This variation of mdr3 cDNA encodes a 7 amino acid, Phe-rich insertion between the putative nucleotide binding sites. In H4638 and H7325, a 0.45 HindII/PstI fragment was used as a probe. |
