Evidence that J-binding protein 2 is a thymidine hydroxylase catalyzing the first step in the biosynthesis of DNA base J.
The genomic DNA of kinetoplastid parasites contains a unique modified base, beta-d-glucosyl-hydroxymethyluracil or base J. We recently reported that two proteins, called J-binding protein (JBP) 1 and 2, which regulate the levels of J in the genome, display features of the family of Fe(II)-2-oxoglutarate dependent dioxygenases and are likely to be the enzymes catalyzing the first step in J biosynthesis. In this study, we examine the effects of replacing the four conserved residues critical for the activity of this class of enzymes on the function of Leishmania tarentolae JBP2. The results show that each of these four residues is indispensable for the ability of JBP2 to stimulate J synthesis, while mutating non-conserved residues has no consequences. We conclude that JBP2, like JBP1, is in all probability a thymidine hydroxylase involved in the biosynthesis of base J.
Vainio
Saara
S
The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands.
Genest
Paul-André
PA
ter Riet
Bas
B
van Luenen
Henri
H
Borst
Piet
P
D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005960:Glucosides / Q000096:biosynthesis*; D007891:Leishmania / Q000201:enzymology* / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013936:Thymidine / Q000378:metabolism*; D014498:Uracil / Q000031:analogs & derivatives* / Q000096:biosynthesis
D016054:DNA, Protozoan; D004268:DNA-Binding Proteins; D005960:Glucosides; C402790:J-specific DNA-binding protein, protozoa; D015800:Protozoan Proteins; C084880:5-((glucopyranosyloxy)methyl)uracil; D014498:Uracil; D006899:Mixed Function Oxygenases; D013936:Thymidine