title: Identification of a plastid intercistronic expression element (IEE) facilitating the expression of stable translatable monocistronic mRNAs from operons.
abstract: Most plastid genes are part of operons and expressed as polycistronic mRNAs. Many primary polycistronic transcripts undergo post-transcriptional processing in monocistronic or oligocistronic units. At least some polycistronic transcripts are not translatable, and endonucleolytic processing may therefore be a prerequisite for translation to occur. As the requirements for intercistronic mRNA processing into stable monocistronic transcript are not well understood, we have sought to define minimum sequence elements that trigger processing and thus are capable of generating stable translatable monocistronic mRNAs. We describe here the in vivo identification of a small intercistronic expression element that mediates intercistronic cleavage into stable monocistronic transcripts. Separation of foreign genes by this element facilitates transgene stacking in operons, and thus will help to expand the range of applications of transplastomic technology.
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie (MPI-MP), Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhou
authors.forename: Daniel
authors.initials: D
authors.lastname: Karcher
authors.forename: Ralph
authors.initials: R
authors.lastname: Bock
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D021901:DNA, Intergenic / Q000737:chemistry; D015870:Gene Expression; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D009876:Operon; D030821:Plants, Genetically Modified / Q000378:metabolism; D018087:Plastids / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D050436:Regulatory Elements, Transcriptional; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D014026:Nicotiana / Q000235:genetics*