TY  - JOUR
T1  - Mitochondrial DNA ligase in Crithidia fasciculata
A1  - Sinha, Krishna Murari
LA  - en
PB  - National Academy of Sciences
YR  - 2004
UL  - http://buscaintegrada.pucsp.br/vufind/Record/pubmed-384752
AB  - Kinetoplast DNA (kDNA), the form of mitochondrial DNA in trypanosomatids, consists of thousands of interlocked circular DNAs organized into a compact disk structure. A type II DNA topoisomerase, a DNA polymerase β, and a structure-specific endonuclease have been localized to antipodal sites flanking the kDNA disk along with nascent DNA minicircles. We have cloned a gene (LIG k) encoding a mitochondrial DNA ligase in the trypanosomatid Crithidia fasciculata, and we show that an epitope-tagged form of the ligase colocalizes with the other replication proteins at the antipodal sites and also at the two faces of the kDNA disk. DNA LIG k becomes adenylated in reactions with ATP, and the adenylate moiety is removed by incubation with pyrophosphate or nicked DNA. The ligase interacts physically with the β polymerase and is proposed to be involved in the repair of gaps in the newly synthesized minicircles. In yeast and mammals, a single gene encodes both nuclear and mitochondrial forms of DNA ligase. The LIG K protein sequence has low similarity to mitochondrial DNA ligases in other eukaryotes and is distinct from the C. fasciculata nuclear DNA ligase (LIG I).
KW  - Biological Sciences
ER  -