Mitochondrial localization of Dictyostelium discoideum dUTPase mediated by its N-terminus
- Univ. of Nebraska, Lincoln, NE (United States). School of Biological Sciences; DOE/OSTI
- Univ. of Alabama, Huntsville, AL (United States). Dept. of Biological Sciences; iXpressGenes Inc, Hudson Alpha Inst. for Biotechnology, Huntsville, AL (United States)
- Univ. of Nebraska, Lincoln, NE (United States). School of Biological Sciences
- Dartmouth College, Hanover, NH (United States). Geisel School of Medicine. Dept. of Molecular and System Biology
Objective: The nuclear and mitochondrial genomes of Dictyostelium discoideum, a unicellular eukaryote, have relatively high A+T-contents of 77.5% and 72.65%, respectively. To begin to investigate how the pyrimidine biosynthetic pathway fulflls the demand for dTTP, we determined the catalytic properties and structure of the key enzyme deoxyuridine triphosphate nucleotidohydrolase (dUTPase) that hydrolyzes dUTP to dUMP, the precursor of dTTP. Results: The annotated genome of D. discoideum identifes a gene encoding a polypeptide containing the fve conserved motifs of homotrimeric dUTPases. Recombinant proteins, comprised of either full-length or core polypeptides with all conserved motifs but lacking residues 1-37 of the N-terminus, were active dUTPases. Crystallographic analyses of the core enzyme indicated that the C-termini, normally flexible, were constrained by interactions with the shortened N-termini that arose from the loss of residues 1-37. This allowed greater access of dUTP to active sites, resulting in enhanced catalytic parameters. A tagged protein comprised of the N-terminal forty amino acids of dUTPase fused to green fluorescent protein (GFP) was expressed in D. discoideum cells. Supporting a prediction of mitochondrial targeting information within the N-terminus, localization and subcellular fractionation studies showed GFP to be in mitochondria. N-terminal sequencing of immunoprecipitated GFP revealed the loss of the dUTPase sequence upon import into the organelle.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER). Biological Systems Science Division
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1629663
- Alternate ID(s):
- OSTI ID: 1833655
- Journal Information:
- BMC Research Notes, Journal Name: BMC Research Notes Journal Issue: 1 Vol. 13; ISSN 1756-0500
- Publisher:
- BioMed CentralCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Active site of mycobacterial dUTPase: Structural characteristics and a built-in sensor
Structural insights into the mechanism defining substrate affinity in Arabidopsis thaliana dUTPase: the role of tryptophan 93 in ligand orientation