Demonstration of mRNA editing and localization of guide RNA genes in kinetoplast–mitochondria of the plant trypanosomatid Phytomonas serpens

• Published in: Molecular and biochemical parasitology 1998-06, Vol.93 (2), p.225-236
• Main Authors: Maslov, Dmitri A, Hollar, Laura, Haghighat, Peyman, Nawathean, Pipat
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Base Sequence; DNA, Kinetoplast - genetics; Genes, Protozoan; Guide RNA; Kinetoplast DNA; Maxicircle; Minicircle; Mitochondria - genetics; Mitochondrial Proteins; Molecular Sequence Data; Phytomonas serpens; Ribosomal protein S12; Ribosomal Proteins - genetics; RNA Editing; RNA, Guide - genetics; RNA, Messenger - genetics; RNA, Protozoan - genetics; Sequence Analysis, DNA; Trypanosomatina - genetics
• ISSN: 0166-6851; 1872-9428
• DOI: 10.1016/S0166-6851(98)00028-0

Maxicircle molecules of kDNA in several isolates of Phytomonas were detected by hybridization with the 12S rRNA gene probe from Leishmania tarentolae. The estimated size of maxicircles is isolate-specific and varies from 27 to 36 kb. Fully edited and polyadenylated mRNA for kinetoplast-encoded ribosomal protein S12 (RPS12) was found in the steady-state kinetoplast RNA isolated from Phytomonas serpens strain 1G. Two minicircles (1.45 kb) from this strain were also sequenced. Each minicircle contains two 120 bp conserved regions positioned 180° apart, a region enriched with G and T bases and a variable region. One minicircle encodes a gRNA for the first block of editing of RPS12 mRNA, and the other encodes a gRNA with unknown function. A gRNA gene for the second block of RPS12 was found on a minicircle sequenced previously. On each minicircle, a gRNA gene is located in the variable region in a similar position and orientation with respect to the conserved regions.