PMID- 10419476
OWN - NLM
STAT- MEDLINE
DCOM- 19990819
LR  - 20190508
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 274
IP  - 31
DP  - 1999 Jul 30
TI  - Yeast and rat Coq3 and Escherichia coli UbiG polypeptides catalyze both
      O-methyltransferase steps in coenzyme Q biosynthesis.
PG  - 21665-72
AB  - Ubiquinone (coenzyme Q or Q) is a lipid that functions in the electron transport 
      chain in the inner mitochondrial membrane of eukaryotes and the plasma membrane
      of prokaryotes. Q-deficient mutants of Saccharomyces cerevisiae harbor defects in
      one of eight COQ genes (coq1-coq8) and are unable to grow on nonfermentable
      carbon sources. The biosynthesis of Q involves two separate O-methylation steps. 
      In yeast, the first O-methylation utilizes 3, 4-dihydroxy-5-hexaprenylbenzoic
      acid as a substrate and is thought to be catalyzed by Coq3p, a 32.7-kDa protein
      that is 40% identical to the Escherichia coli O-methyltransferase, UbiG. In this 
      study, farnesylated analogs corresponding to the second O-methylation step,
      demethyl-Q(3) and Q(3), have been chemically synthesized and used to study Q
      biosynthesis in yeast mitochondria in vitro. Both yeast and rat Coq3p recognize
      the demethyl-Q(3) precursor as a substrate. In addition, E. coli UbiGp was
      purified and found to catalyze both O-methylation steps. Futhermore, antibodies
      to yeast Coq3p were used to determine that the Coq3 polypeptide is peripherally
      associated with the matrix-side of the inner membrane of yeast mitochondria. The 
      results indicate that one O-methyltransferase catalyzes both steps in Q
      biosynthesis in eukaryotes and prokaryotes and that Q biosynthesis is carried out
      within the matrix compartment of yeast mitochondria.
FAU - Poon, W W
AU  - Poon WW
AD  - Department of Chemistry and Biochemistry and the Molecular Biology Institute,
      University of California, Los Angeles, California 90095, USA.
FAU - Barkovich, R J
AU  - Barkovich RJ
FAU - Hsu, A Y
AU  - Hsu AY
FAU - Frankel, A
AU  - Frankel A
FAU - Lee, P T
AU  - Lee PT
FAU - Shepherd, J N
AU  - Shepherd JN
FAU - Myles, D C
AU  - Myles DC
FAU - Clarke, C F
AU  - Clarke CF
LA  - eng
GR  - GM07185/GM/NIGMS NIH HHS/United States
GR  - GM45952/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Escherichia coli Proteins)
RN  - 0 (Indicators and Reagents)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 1339-63-5 (Ubiquinone)
RN  - EC 2.1.1.- (Methyltransferases)
RN  - EC 2.1.1.- (UbiG protein, E coli)
RN  - EC 2.1.1.114 (3,4-dihydroxy-5-hexaprenylbenzoate methyltransferase)
SB  - IM
MH  - Animals
MH  - Chromatography, High Pressure Liquid
MH  - Cloning, Molecular
MH  - Escherichia coli/*enzymology
MH  - *Escherichia coli Proteins
MH  - Indicators and Reagents
MH  - Methyltransferases/*metabolism
MH  - Rats
MH  - Recombinant Fusion Proteins/metabolism
MH  - Saccharomyces cerevisiae/*enzymology
MH  - Ubiquinone/*biosynthesis/*chemical synthesis
EDAT- 1999/07/27 00:00
MHDA- 1999/07/27 00:01
CRDT- 1999/07/27 00:00
PHST- 1999/07/27 00:00 [pubmed]
PHST- 1999/07/27 00:01 [medline]
PHST- 1999/07/27 00:00 [entrez]
AID - 10.1074/jbc.274.31.21665 [doi]
PST - ppublish
SO  - J Biol Chem. 1999 Jul 30;274(31):21665-72. doi: 10.1074/jbc.274.31.21665.