TY - JOUR
T1 - The role of UbiX in Escherichia coli coenzyme Q biosynthesis
AU - Gulmezian, Melissa
AU - Hyman, Kyle R.
AU - Marbois, Beth N.
AU - Clarke, Catherine F.
AU - Javor, George T.
N1 - Funding Information:
We express our thanks to Dr. George Church for sending us the pKO3 plasmid; Dr. Valeri Fillipov for performing the RT-PCR assays; Drs. Kylie Watts, Mark Johnson, Jun-ichi Ryu and Istvan Fodor for advice on gene knockout strategies; Gordon Harding, Liubov Litvinkova, Farnosh Family, Odi Osonkie for helpful suggestions and Dr. Bradley C. Hyman for comments on the manuscript. This work was supported by National Institutes of Health Grant GM45952 (to C.F. Clarke) and by a grant from Loma Linda School of Medicine (to G.T. Javor).
PY - 2007/11/15
Y1 - 2007/11/15
N2 - The reversible redox chemistry of coenzyme Q serves a crucial function in respiratory electron transport. Biosynthesis of Q in Escherichia coli depends on the ubi genes. However, very little is known about UbiX, an enzyme thought to be involved in the decarboxylation step in Q biosynthesis in E. coli and Salmonella enterica. Here we characterize an E. coli ubiX gene deletion strain, LL1, to further elucidate E. coli ubiX function in Q biosynthesis. LLI produces very low levels of Q, grows slowly on succinate as the sole carbon source, accumulates 4-hydroxy-3-octaprenyl-benzoate, and has reduced UbiG O-methyltransferase activity. Expression of either E. coli ubiX or the Saccharomyces cerevisiae ortholog PAD1, rescues the deficient phenotypes of LL1, identifying PAD1 as an ortholog of ubiX. Our results suggest that both UbiX and UbiD are required for the decarboxylation of 4-hydroxy-3-octaprenyl-benzoate in E. coli coenzyme Q biosynthesis, especially during logarithmic growth.
AB - The reversible redox chemistry of coenzyme Q serves a crucial function in respiratory electron transport. Biosynthesis of Q in Escherichia coli depends on the ubi genes. However, very little is known about UbiX, an enzyme thought to be involved in the decarboxylation step in Q biosynthesis in E. coli and Salmonella enterica. Here we characterize an E. coli ubiX gene deletion strain, LL1, to further elucidate E. coli ubiX function in Q biosynthesis. LLI produces very low levels of Q, grows slowly on succinate as the sole carbon source, accumulates 4-hydroxy-3-octaprenyl-benzoate, and has reduced UbiG O-methyltransferase activity. Expression of either E. coli ubiX or the Saccharomyces cerevisiae ortholog PAD1, rescues the deficient phenotypes of LL1, identifying PAD1 as an ortholog of ubiX. Our results suggest that both UbiX and UbiD are required for the decarboxylation of 4-hydroxy-3-octaprenyl-benzoate in E. coli coenzyme Q biosynthesis, especially during logarithmic growth.
KW - Coenzyme Q biosynthesis
KW - Decarboxylase
KW - Escherichia coli
KW - PAD1
KW - Saccharomyces cerevisiae
KW - Ubiquinone
KW - YDR538W
KW - YDR539W
KW - ubiD
KW - ubiX
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U2 - 10.1016/j.abb.2007.08.009
DO - 10.1016/j.abb.2007.08.009
M3 - Article
C2 - 17889824
SN - 0003-9861
VL - 467
SP - 144
EP - 153
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 2
ER -