Purification and partial characterization of 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase and 7,8-dihydropteroate synthase from Escherichia coli MC4100.
The enzymes 7,8-dihydroxymethylpterin-pyrophosphokinase (HPPK) and 7,8-dihydropteroate synthase (DHPS), which act sequentially in the folate pathway, were purified to homogeneity from crude extracts of Escherichia coli MC4100. The enzymes represent less than 0.01% of the total soluble protein. HPPK was purified greater than 10,000-fold; the native enzyme appears to be a monomer with a molecular mass of 25 kDa and a pI of 5.2. DHPS was purified greater than 7,000-fold; the native enzyme has an apparent molecular mass of 52 to 54 kDa and is composed of two identical 30-kDa subunits. The amino-terminal sequences for both enzymes have been determined.
Talarico
T L
TL
Division of Molecular Genetics and Microbiology, Wellcome Research Laboratories, Research Triangle Park, North Carolina 27709.
Dev
I K
IK
Dallas
W S
WS
Ferone
R
R
Ray
P H
PH
D000595:Amino Acid Sequence; D004094:Dihydropteroate Synthase / Q000302:isolation & purification* / Q000378:metabolism; D017854:Diphosphotransferases; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology*; D008969:Molecular Sequence Data; D010770:Phosphotransferases / Q000302:isolation & purification* / Q000378:metabolism
D004094:Dihydropteroate Synthase; D010770:Phosphotransferases; D017854:Diphosphotransferases; C019684:2-amino-4-hydroxy-6-hydroxymethyldihydropteridine pyrophosphokinase