Annotation and characterization of Babesia gibsoni apicoplast genome

Abstract

Background: Babesia gibsoni is an apicomplexan parasite transmitted by ticks, which can infect canine species and cause babesiosis. The apicoplast is an organelle associated with isoprenoids metabolism, is widely present in apicomplexan parasites, except for Cryptosporidium. Available data indicate that the apicoplast is essential for the survival of apicomplexan parasites. Methods: Here, the apicoplast genome of B. gibsoni was investigated by high-throughput genome sequencing, bioinformatics analysis, and conventional PCR. Results: The apicoplast genome of B. gibsoni-Wuhan strain (B. gibsoni-WH) consists of a 28.4 kb circular molecule, with A + T content of 86.33%, similar to that of B. microti. Specifically, this genome encodes genes involved in maintenance of the apicoplast DNA, transcription, translation and maturation of organellar proteins, which contains 2 subunits of ribosomal RNAs, 17 ribosomal proteins, 1 EF-Tu elongation factor (tufA), 5 DNA-dependent RNA polymerase beta subunits, 2 Clp protease chaperones, 23 tRNA genes and 5 unknown open reading frames (hypothetical proteins). Phylogenetic analysis revealed high similarity of B. gibsoni apicoplast genome to that of B. orientalis and B. bovis. Conclusions: To our knowledge, this is the first report of annotation and characterization of B. gibsoni-WH apicoplast genome. The results will facilitate the development of new anti-Babesia drug targets.

A pyruvate transporter in the apicoplast of apicomplexan parasites

“…Pyruvate is an essential metabolite in the apicoplast, so are amino acids. The apicoplast has a genome encoding many proteins, translation of which require amino acids ( 70 – 72 ). So far, all the ApiAT family amino acid transporters identified in T. gondii are localized to the plasma membrane ( 73 ).…”

Coordination of apicoplast transcription in a malaria parasite by internal and host cues

“…In gregarines, the apicoplast is lost ( 42 , 43 ). The structure of the apicoplast genome of piroplasmids differs from the general plastid genome because all genes, including those of rRNAs and tRNAs, occupy one strand of the genome ( 44 ). Probably, a different mechanism that does not involve σ subunit regulates apicoplast gene expression in piroplasmids.…”