Chloroplast ribosomes and protein synthesis.

Abstract

ORIGIN OF CHLOROPLASTS Chloroplasts and mitochondria contain protein synthesizingsystems more similar to those of bacteria than to those of the eukaryotic cytoplasm, consistent with the hypothesis that these organelles had xenogenous (endosymbiotic) rather than autogenous (intracellular differentiation) origins (see. references 5, 205, 220-223, 274, 633, and 694 for discussions). Phylogenies based mostly on rRNA sequences indicate that the cyanobacteria are ancestral to chloroplasts while the members of the alpha subdivision of the purple sulfur bacteria are the likely progenitors of mitochondria (221, 222). Whether the, chlorophyte algae and land plants on the one hand, and the rhodophyte, chromophyte, and euglenoid algae on the other represent more than one endosymbiotic event remains unresolved (130, 403, 434). Comparisons of gene order and arrangement

The essential chloroplast ribosomal protein uL15c interacts with the chloroplast RNA helicase ISE2 and affects intercellular trafficking through plasmodesmata

“…(The new nomenclature for ribosomal proteins has been adopted herein (Ban et al, 2014)). A distinguishing characteristic of chloroplast ribosomal RNA (rRNA) of some green algae and all land plants is the presence of a 4.5S rRNA that is similar to the 3 0 end of the bacterial 23S rRNA and other RNA species (Harris et al, 1994). Despite this difference, the nascent 23S rRNAs of the bacterial and chlororibosomes are still of similar size, c. 4500 nucleotides.…”

Cis-acting elements and trans-acting factors for accurate translation of chloroplast psbA mRNAs: development of an in vitro translation system from tobacco chloroplasts.

“…Chloroplasts have their own translation system, consisting of 70S-type ribosomes,~30 tRNA species, initiation/ elongation factors (e.g. IF-1, EF-Tu and EF-G) and aminoacyl-tRNA synthetases which are highly homologous to those in prokaryotes (Sugiura, 1992;Subramanian, 1993;Gillham et al, 1994;Harris et al, 1994). Despite these structural similarities, the chloroplast translation system has several features distinct from those in prokaryotes.…”

UNIVERSAL PRIMERS AMPLIFY A 23S rDNA PLASTID MARKER IN EUKARYOTIC ALGAE AND CYANOBACTERIA1

“…The data include 107 algal representatives from the red, green, and brown algae, as well as the diatoms, euglenoids, xanthophytes, and cyanobacteria. GenBank accession numbers and species authorities are provided in Supplementary Table S1. flank Domain V of the 23S plastid rRNA gene (Harris et al 1994). Here we demonstrate the ease of using a single pair of universal primers for amplification and sequencing of this plastid marker for multiple eukaryotic algal and cyanobacterial groups, present a preliminary DNA sequence framework based on these data, and illustrate the taxonomic level at which it distinguishes taxa for at least some algal lineages.…”