Advertisement

Current Genetics

, Volume 36, Issue 1–2, pp 49–54 | Cite as

Expression of the two chloroplast-like tRNAAsn genes in potato mitochondria: mapping of transcription initiation sites present in the trnN1-trnY-nad2 cluster and upstream of trnN2

  • Julien Fey
  • Laurence Maréchal-Drouard
ORIGINAL PAPER

Abstract

Two copies of the chloroplast-like tRNAAsn gene, trnN1 and trnN2, are expressed in potato mitochondria. While Northern-blot analysis revealed only mature tRNAAsn, RT-PCR indicated that trnN1 is co-transcribed with trnY and nad2 (exons c, d and e). Using primer-extension and capping experiments, four transcription initiation sites have been mapped in the vicinity of these genes. The first site, responsible for the co-transcription of trnN1, trnY and nad2 (exons c, d and e), gives rise to a primary transcript of at least 7000 nt. A second site, 58 nt downstream from trnY, corresponds to an alternative promoter specific for nad2. In both cases, only the CRTA core motif of the consensus CRTAaGaGA of dicot mitochondrial promoters was found. Finally, two transcription initiation sites were identified 135 and 128 nt upstream of trnN2 in a region which shows no sequence homology with this consensus motif.

Key words Chloroplast-like tRNA gene nad2 Plant mitochondrial promoter 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Julien Fey
    • 1
  • Laurence Maréchal-Drouard
    • 1
  1. 1.Institut de Biologie Moléculaire des Plantes du CNRS, UPR A0406 du CNRS, Université Louis Pasteur, 12 rue du Général Zimmer, F-67084 Strasbourg Cedex, France e-mail: laurence.drouard@ibmp-ulp.u-strasbg.fr Tel.: +33-3-88 41 72 27; Fax: +33-3-61 44 42FR

Personalised recommendations