Role of p38 in replication of Trypanosoma brucei kinetoplast DNA.

نویسندگان

  • Beiyu Liu
  • Henrik Molina
  • Dario Kalume
  • Akhilesh Pandey
  • Jack D Griffith
  • Paul T Englund
چکیده

Trypanosomes have an unusual mitochondrial genome, called kinetoplast DNA, that is a giant network containing thousands of interlocked minicircles. During kinetoplast DNA synthesis, minicircles are released from the network for replication as theta-structures, and then the free minicircle progeny reattach to the network. We report that a mitochondrial protein, which we term p38, functions in kinetoplast DNA replication. RNA interference (RNAi) of p38 resulted in loss of kinetoplast DNA and accumulation of a novel free minicircle species named fraction S. Fraction S minicircles are so underwound that on isolation they become highly negatively supertwisted and develop a region of Z-DNA. p38 binds to minicircle sequences within the replication origin. We conclude that cells with RNAi-induced loss of p38 cannot initiate minicircle replication, although they can extensively unwind free minicircles.

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عنوان ژورنال:
  • Molecular and cellular biology

دوره 26 14  شماره 

صفحات  -

تاریخ انتشار 2006