Trypanosoma brucei brucei: thymine 7-hydroxylase-like proteins.
Two genes from Trypanosoma brucei brucei are predicted to encode Fe(II)- and alpha-ketoglutarate-dependent enzymes related to fungal thymine 7-hydroxylase. Transcription of the thymine hydroxylase-like genes is up-regulated in the bloodstream form of the parasite over the insect form, whereas Western blot analysis indicates more cross-reactive protein in the latter life stage. The genes were cloned, the proteins purified from Escherichia coli, and both proteins were shown to bind Fe(II) and alpha-ketoglutarate, confirming proper folding. The isolated proteins were incubated with Fe(II)- and alpha-ketoglutarate plus thymine, thymidine, and other putative substrates, but no activity was detected. Furthermore, no thymine 7-hydroxylase activity was detected in extracts of procyclic or bloodstream form cells. Although the functions of these proteins remain unknown, we conclude they are unlikely to be involved in thymine salvage.
Simmons
Jana M
JM
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States.
Koslowsky
Donna J
DJ
Hausinger
Robert P
RP
D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000276:immunology; D015153:Blotting, Western; D004926:Escherichia coli / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D015971:Gene Expression Regulation, Enzymologic; D007527:Isoenzymes / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D011817:Rabbits; D012248:Rhodotorula / Q000201:enzymology / Q000235:genetics; D013056:Spectrophotometry, Ultraviolet; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000235:genetics / Q000276:immunology
D000913:Antibodies, Protozoan; D007527:Isoenzymes; D015800:Protozoan Proteins; D006899:Mixed Function Oxygenases; C023164:thymine, 2-oxoglutarate dioxygenase