Characterisation of kinetoplast DNA minicircles from Herpetomonas samuelpessoai

In this study, we have sequenced more than 100 clones of minicircle DNA fro m Herpetomonas samuelpessoai. An unusual amplification approach was develop ed to amplify minicircle DNA by using a pair of complementary primers desig ned from a universal stretch of minicircle sequence. Sequence analysis show s that the kinetoplast minicircles in Herpetomonas with a size of 1.3 kb ar e organised into two conserved regions and two variable regions which are l ocated 180 degrees apart. The potential gRNA genes are encoded in variable regions of minicircle approximately 360 bp from CSB-3 (conserved sequence b lock 3). A conserved upstream sequence located 30 nt before the gRNA genes was identified and is related to the gRNA genes in sequence organisation. A potential role(s) of this sequence in gRNA transcription is discussed. (C) 1999 Published by Elsevier Science B.V, All rights reserved.