Mammalian multidrug resistance gene: complete cDNA sequence indicates strong homology to bacterial transport proteins

Cell. 1986 Nov 7;47(3):371-80. doi: 10.1016/0092-8674(86)90594-5.


The complete nucleotide and primary structure (1276 amino acids) of a full length mdr cDNA capable of conferring a complete multidrug-resistant phenotype is presented. The deduced amino acid sequence suggests that mdr is a membrane glycoprotein which includes six pairs of transmembrane domains and a cluster of potentially N-linked glycosylation sites near the amino terminus. A striking feature of the protein is an internal duplication that includes approximately 500 amino acids. Each duplicated segment includes a consensus ATP-binding site. Amino acid homology is observed between the mdr gene and a series of bacterial transport genes. This strong homology suggests that a highly conserved functional unit involved in membrane transport is present in the mdr polypeptide. We propose that an energy-dependent transport mechanism is responsible for the multidrug-resistant phenotype.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Biological Transport, Active
  • DNA / analysis*
  • Drug Resistance / genetics*
  • Glycoproteins / analysis
  • Glycoproteins / genetics
  • Mammals
  • Membrane Proteins / analysis
  • Membrane Proteins / genetics
  • Peptides / analysis
  • Phenotype


  • Bacterial Proteins
  • Glycoproteins
  • Membrane Proteins
  • Peptides
  • DNA

Associated data

  • GENBANK/M14757