@article {385, title = {Closing the gaps in kinetoplast DNA network replication.}, journal = {Proc Natl Acad Sci U S A}, volume = {101}, year = {2004}, month = {2004 Mar 30}, pages = {4333-4}, keywords = {Animals, Crithidia fasciculata, DNA Ligases, DNA Replication, DNA, Kinetoplast, DNA, Mitochondrial, Microscopy, Electron, Trypanosoma brucei brucei}, issn = {0027-8424}, doi = {10.1073/pnas.0401400101}, author = {Klingbeil, Michele M and Englund, Paul T} } @article {386, title = {Trypanosoma brucei has two distinct mitochondrial DNA polymerase beta enzymes.}, journal = {J Biol Chem}, volume = {278}, year = {2003}, month = {2003 Dec 5}, pages = {49095-101}, abstract = {In higher eukaryotes, DNA polymerase (pol) beta resides in the nucleus and participates primarily in DNA repair. The DNA polymerase beta from the trypanosomatid Crithidia fasciculata, however, was the first mitochondrial enzyme of this type described. Upon searching the nearly completed genome data base of the related parasite Trypanosoma brucei, we discovered genes for two pol beta-like proteins. One is approximately 70\% identical to the C. fasciculata pol beta and is likely the homolog of this enzyme. The other, although approximately 30\% identical within the polymerase region, has unusual structural features including a short C-terminal tail and a long N-terminal extension rich in prolines, alanines, and lysines. Both proteins, when expressed recombinantly, are active as DNA polymerases and deoxyribose phosphate lyases, but their polymerase activity optima differ with respect to pH and KCl and MgCl2 concentrations. Remarkably, green fluorescent protein fusion proteins and immunofluorescence demonstrate that both are mitochondrial, but their locations with respect to the mitochondrial DNA (kinetoplast DNA network) in this organism are strikingly different.}, keywords = {Animals, Base Sequence, Cell Line, DNA Polymerase beta, DNA Primers, Isoenzymes, Mitochondria, Recombinant Proteins, Trypanosoma brucei brucei}, issn = {0021-9258}, doi = {10.1074/jbc.M308565200}, author = {Saxowsky, Tina T and Choudhary, Gunjan and Klingbeil, Michele M and Englund, Paul T} } @article {388, title = {Multiple mitochondrial DNA polymerases in Trypanosoma brucei.}, journal = {Mol Cell}, volume = {10}, year = {2002}, month = {2002 Jul}, pages = {175-86}, abstract = {Kinetoplast DNA (kDNA), the unusual mitochondrial DNA of Trypanosoma brucei, is a network containing thousands of catenated circles. Database searching for a kDNA replicative polymerase (pol) revealed no mitochondrial pol gamma homolog. Instead, we identified four proteins (TbPOLIA, IB, IC, and ID) related to bacterial pol I. Remarkably, all four localized to the mitochondrion. TbPOLIB and TbPOLIC localized beside the kDNA where replication occurs, and their knockdown by RNA interference caused kDNA network shrinkage. Furthermore, silencing of TbPOLIC caused loss of both minicircles and maxicircles and accumulation of minicircle replication intermediates, consistent with a role in replication. While typical mitochondria contain one DNA polymerase, pol gamma, trypanosome mitochondria contain five such enzymes, including the previously characterized pol beta.}, keywords = {Amino Acid Sequence, Animals, DNA, Kinetoplast, DNA-Directed DNA Polymerase, Mitochondria, Molecular Sequence Data, Phylogeny, Protein Structure, Tertiary, Protein Transport, RNA, Double-Stranded, RNA, Messenger, Sequence Homology, Amino Acid, Trypanosoma brucei brucei}, issn = {1097-2765}, author = {Klingbeil, Michele M and Motyka, Shawn A and Englund, Paul T} }