PfKsgA1 functions as a transcription initiation factor and interacts with the N-terminal region of the mitochondrial RNA polymerase of Plasmodium falciparum.

PfKsgA1 functions as a transcription initiation factor and interacts with the N-terminal region of the mitochondrial RNA polymerase of Plasmodium falciparum. Int J Parasitol. 2020 Sep 04;: Authors: Gupta A, Shrivastava D, Kumar Shakya A, Gupta K, Pratap JV, Habib S Abstract The small mitochondrial genome (mtDNA) of the malaria parasite is known to transcribe its genes polycistonically, although promoter element(s) have not yet been identified. An unusually large Plasmodium falciparum candidate mitochondrial phage-like RNA polymerase (PfmtRNAP) with an extended N-terminal region is encoded by the parasite nuclear genome. Using specific antibodies against the enzyme, we established that PfmtRNAP was targeted exclusively to the mitochondrion and interacted with mtDNA. Phylogenetic analysis showed that it is part of a separate apicomplexan clade. A search for PfmtRNAP-associated transcription initiation factors using sequence homology and in silico protein-protein interaction network analysis identified PfKsgA1. PfKsgA1 is a dual cytosol- and mitochondrion-targeted protein that functions as a small subunit (SSU) rRNA dimethyltransferase in ribosome biogenesis. Chromatin immunoprecipitation showed that PfKsgA1 interacts with mtDNA, and in vivo crosslinking and pull-down experiments confirmed PfmtRNAP-PfKsgA1 interaction. The ability of PfKsgA1 to serve as a transcription initiation factor was demonstrated by complementation of yeast mitoc...
Source: International Journal for Parasitology - Category: Parasitology Authors: Tags: Int J Parasitol Source Type: research