Unwinding maxicircle DNA

DNA unwinding via minichromosome maintenance

Minichromosome maintenance (MCM) proteins play an essential role in DNA unwinding and are completely conserved throughout eukaryotic and archaeal cells, underscoring their fundamental importance in DNA replication. Biochemists have characterized some of the protein motifs that affect the unwinding of DNA by MCM proteins. Elizabeth Jenkinson and James Chong studied how changes in the MCM protein...

On the Unwinding of Dna.

Isolation of maxicircle component of kinetoplast DNA from hemoflagellate protozoa.

Maxicircle DNA has been isolated from the kinetoplast DNA of Leishmania tarentolae culture forms by bouyant separation in CsCl in the presence of the A + T-binding dye Hoechst 33258, after liberation from the kinetoplast DNA network by cleavage with the single-hit restriction endonuclease EcoRI. The purified linearized maxicircle DNA has a density in CsCl of 1.681 g/cm3 (79% A + T) and a molecu...

Maxicircle DNA and edited mRNA sequences of closely related trypanosome species: implications of kRNA editing for evolution of maxicircle genomes.

kRNA editing produces functional mRNAs by uridine insertion and deletion. We analyzed portions of the apocytochrome b and NADH dehydrogenase subunits 7 and 8 (ND7 and 8) genes and their edited mRNAs in Trypanosoma congolense and compared these to the corresponding sequences in T.brucei. We find that these genes are highly diverged between the two species, especially in the positions of thymidin...

Mechanisms of helicase-catalyzed DNA unwinding.

DNA helicases are essential motor proteins that function to unwind duplex DNA to yield the transient single-stranded DNA intermediates required for replication, recombination, and repair. These enzymes unwind duplex DNA and translocate along DNA in reactions that are coupled to the binding and hydrolysis of 5'-nucleoside triphosphates (NTP). Although these enzymes are essential for DNA metaboli...