COQ2 is a candidate for the structural gene encoding para-hydroxybenzoate:polyprenyltransferase

J Biol Chem. 1992 Feb 25;267(6):4128-36.


Coenzyme Q functions as a lipid-soluble electron carrier in eukaryotes. In Saccharomyces cerevisiae, the enzymes responsible for the assembly of the polyisoprenoid side chain and subsequent transfer to para-hydroxybenzoate (PHB) are encoded by the nuclear genes COQ1 and COQ2, respectively. Yeast mutants defective in coenzyme Q biosynthesis are respiratory defective and provide a useful tool to study this non-sterol branch of the isoprenoid biosynthetic pathway. We isolated a 5.5-kilobase genomic DNA fragment that was able to functionally complement a coq2 strain. Additional complementation analyses located the COQ2 gene within a 2.1-kilobase HindIII-BglII restriction fragment. Sequence analyses revealed the presence of a 1,116-base pair open reading frame coding for a predicted protein of 372 amino acids and a molecular mass of 41,001 daltons. The amino acid sequence exhibits a typical amino-terminal mitochondrial leader sequence and six potential membrane-spanning domains. Primer extension and Northern analyses indicate the gene is transcriptionally active. Transformation of a coq2 strain with the 2.1-kilobase HindIII-BglII genomic restriction fragment on a multicopy plasmid restores PHB:polyprenyltransferase activity to wild-type levels. Disruption of the chromosomal COQ2 gene indicates the gene is not essential for viability, yet is required for PHB:polyprenyltransferase activity and respiratory function. In addition, the deduced amino acid sequence of PHB:polyprenyltransferase contains a putative allylic polyprenyl diphosphate-binding site. The presence of this aspartate-rich domain in a number of functionally distinct proteins which utilize polyprenyl diphosphate substrates is reported.

Publication types

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

MeSH terms

  • Alkyl and Aryl Transferases*
  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Cloning, Molecular
  • DNA, Fungal
  • Genes, Fungal*
  • Molecular Sequence Data
  • Open Reading Frames
  • Plasmids
  • Restriction Mapping
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics
  • Sequence Homology, Nucleic Acid
  • Transferases / genetics*
  • Transferases / metabolism
  • Ubiquinone / genetics*


  • DNA, Fungal
  • Ubiquinone
  • Transferases
  • Alkyl and Aryl Transferases
  • 4-hydroxybenzoate polyprenyltransferase

Associated data

  • GENBANK/L01671
  • GENBANK/L01672
  • GENBANK/L01673
  • GENBANK/L01674
  • GENBANK/L01675
  • GENBANK/L01676
  • GENBANK/L01677
  • GENBANK/M81698
  • GENBANK/X59129
  • GENBANK/X59130