Chloroplast initiation factor 3 from Euglena gracilis. Identification and initial characterization.
A chloroplast ribosome dissociation factor (IF-3chl) has been identified in whole cell extracts of Euglena gracilis. This work represents the first report of an organellar ribosome dissociation factor. E. gracilis IF-3chl facilitates the dissociation of Escherichia coli ribosomes as demonstrated by sucrose density gradient analysis. Chloroplast IF-3 stimulates initiation complex formation on E. coli ribosomes with natural mRNA from the bacteriophage MS2. In addition, IF-3chl is effective in initiation complex formation with Euglena chloroplast or E. coli ribosomes in the presence of synthetic mRNA. IF-3chl is induced 12-fold by exposure of the cells to light. The chloroplast factor has been purified 30-fold by chromatography on DEAE-cellulose and phosphocellulose. The chromatographic properties of this factor differ considerably from those of prokaryotic ribosome dissociation factors.
Kraus
B L
BL
Spremulli
L L
LL
D000818:Animals; D002499:Centrifugation, Density Gradient; D002736:Chloroplasts / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D004926:Escherichia coli / Q000648:ultrastructure; D005056:Euglena gracilis / Q000032:analysis*; D015852:Eukaryotic Initiation Factor-2; D008970:Molecular Weight; D010448:Peptide Initiation Factors / Q000032:analysis / Q000494:pharmacology*; D039665:Prokaryotic Initiation Factor-3; D011506:Proteins / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012358:RNA, Transfer, Met; D012270:Ribosomes / Q000378:metabolism
D015852:Eukaryotic Initiation Factor-2; D010448:Peptide Initiation Factors; D039665:Prokaryotic Initiation Factor-3; D011506:Proteins; D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl; D012358:RNA, Transfer, Met; C024988:tRNA, formylmethionine-