title: Chloroplast RNA metabolism.
abstract: The chloroplast genome encodes proteins required for photosynthesis, gene expression, and other essential organellar functions. Derived from a cyanobacterial ancestor, the chloroplast combines prokaryotic and eukaryotic features of gene expression and is regulated by many nucleus-encoded proteins. This review covers four major chloroplast posttranscriptional processes: RNA processing, editing, splicing, and turnover. RNA processing includes the generation of transcript 5' and 3' termini, as well as the cleavage of polycistronic transcripts. Editing converts specific C residues to U and often changes the amino acid that is specified by the edited codon. Chloroplasts feature introns of groups I and II, which undergo protein-facilitated cis- or trans-splicing in vivo. Each of these RNA-based processes involves proteins of the pentatricopeptide motif-containing family, which does not occur in prokaryotes. Plant-specific RNA-binding proteins may underpin the adaptation of the chloroplast to the eukaryotic context.
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA. ds28@cornell.edu
authors.forename: David B
authors.initials: DB
authors.lastname: Stern
authors.forename: Michel
authors.initials: M
authors.lastname: Goldschmidt-Clermont
authors.forename: Maureen R
authors.initials: MR
authors.lastname: Hanson
mesh_terms: D020816:Amino Acid Motifs; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D018747:RNA, Chloroplast / Q000235:genetics* / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D018747:RNA, Chloroplast; D016601:RNA-Binding Proteins