Site-directed mutagenesis of the yeast mitochondrial ADP/ATP translocator. Six arginines and one lysine are essential

J Mol Biol. 1993 Apr 20;230(4):1159-70. doi: 10.1006/jmbi.1993.1233.


The ADP/ATP translocator mediates adenine nucleotide exchange across the inner mitochondrial membrane. ADP/ATP exchange is essential when yeast are grown on a non-fermentable carbon source such as glycerol, but it is not required for growth on glucose. Failure to grow on glycerol is therefore a phenotypic indicator of protein function, and it has been used here to screen site-directed mutants to identify functionally important amino acids in the yeast adenine nucleotide translocator (AAC2). Single mutations of all four charged amino acids in the transmembrane segments of AAC2 (K38A, R96D, R96H, R96L, R96P, R204L, R294A) resulted in loss of function, as did mutations in the matrix arginine cluster (R252I, R253I, R254I). Seven other residues were mutated without affecting growth on glycerol (C73S, C244S, C271S, K179M, K182I, P247G, W235F). The non-functional mutants have been used to select intragenic suppressors to gain further insight into the structure of this membrane transport protein.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Carrier Proteins / classification
  • Carrier Proteins / genetics*
  • Cell Fractionation
  • DNA Mutational Analysis
  • Fungal Proteins / classification
  • Fungal Proteins / genetics*
  • Gene Deletion
  • Mitochondria / physiology*
  • Mitochondrial ADP, ATP Translocases / genetics*
  • Models, Molecular
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics*
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Structure-Activity Relationship


  • Carrier Proteins
  • Fungal Proteins
  • Mitochondrial ADP, ATP Translocases

Associated data

  • GENBANK/D12637
  • GENBANK/M75842
  • GENBANK/M79540
  • GENBANK/M79591
  • GENBANK/M79804
  • GENBANK/M79805
  • GENBANK/M79867
  • GENBANK/M79868
  • GENBANK/M80064
  • GENBANK/M89114
  • GENBANK/M89246
  • GENBANK/X60036
  • GENBANK/X65194