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Role of p38 in replication of Trypanosoma brucei kinetoplast DNA.

ABSTRACT: 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.

SUBMITTER: Liu B

PROVIDER: S-EPMC1592711 | biostudies-literature | 2006 Jul

REPOSITORIES: biostudies-literature

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Role of p38 in replication of Trypanosoma brucei kinetoplast DNA.

Liu Beiyu B Molina Henrik H Kalume Dario D Pandey Akhilesh A Griffith Jack D JD Englund Paul T PT

Molecular and cellular biology 20060701 14

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 accum ...[more]

PMID: 16809774

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