Clustering of disease-causing mutations on the domain-domain interfaces of ABCC6

Biochem Biophys Res Commun. 2009 Feb 13;379(3):706-9. doi: 10.1016/j.bbrc.2008.12.142. Epub 2009 Jan 6.


Mutations in ABCC6 are responsible for pseudoxanthoma elasticum (PXE), a rare genetic disease affecting the elastic tissues of the body. ABCC6 encodes a 1503 amino acid long ABC transporter, ABCC6/MRP6. The functional link between the impaired activity of the protein and the disease is not known. We have built a homology model of this transporter, and analyzed the distribution of the known 119 missense PXE-associated mutations within the predicted structure. Significant clustering of the missense mutations has been found at complex domain-domain interfaces: at the transmission interface that involves four intracellular loops and the two ABC domains as well as at the ABC-ABC interacting surfaces. The mutations affecting these regions are 2.75 and 3.53-fold more frequent than the average mutational rate along the transporter protein sequence. These data provide a genetic proof of the importance of these domain-domain interactions in the ABCC6 transporter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Membrane / chemistry
  • Cell Membrane / metabolism
  • Cluster Analysis
  • Humans
  • Models, Chemical*
  • Multidrug Resistance-Associated Proteins / chemistry*
  • Multidrug Resistance-Associated Proteins / genetics*
  • Multidrug Resistance-Associated Proteins / metabolism
  • Mutation, Missense*
  • Protein Structure, Tertiary / genetics
  • Pseudoxanthoma Elasticum / genetics*
  • Sequence Homology


  • ABCC6 protein, human
  • Multidrug Resistance-Associated Proteins