A dominant mutation in the Chlamydomonas reinhardtii nuclear gene SIM30 suppresses translational defects caused by initiation codon mutations in chloroplast genes.
A suppressor of a translation initiation defect caused by an AUG to AUU mutation in the Chlamydomonas reinhardtii chloroplast petD gene was isolated, defining a nuclear locus that we have named SIM30. A dominant mutant allele at this locus, sim30-1d, was found to increase the translation initiation rate of the mutant petD mRNA. sim30-1d was also able to suppress the translational defect caused by an AUG to AUC mutation in the petD gene, and an AUG to AUU mutation in the chloroplast petA gene. We therefore suggest that the SIM30 gene may encode a general chloroplast translation factor. The ability of sim30-1d to suppress the petD AUG to AUU mutation is diminished in the presence of one or more antibiotic resistance markers located within the 16S and 23S rRNAs, suggesting that the activity of the sim30-1d gene product in translation initiation may involve interaction with ribosomal subunits.
Chen
X
X
Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, New York 14853, USA.
Simpson
C L
CL
Kindle
K L
KL
Stern
D B
DB
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000235:genetics*; D002736:Chloroplasts / Q000235:genetics*; D003062:Codon / Q000235:genetics*; D003573:Cytochrome b Group / Q000235:genetics; D045346:Cytochrome b6f Complex; D004352:Drug Resistance, Microbial / Q000235:genetics; D005786:Gene Expression Regulation; D018506:Gene Expression Regulation, Plant; D005799:Genes, Dominant; D017343:Genes, Plant; D017125:Genes, Protozoan; D016153:Genes, Suppressor; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D015800:Protozoan Proteins / Q000235:genetics* / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics; D016053:RNA, Protozoan / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid
D003062:Codon; D003573:Cytochrome b Group; D010940:Plant Proteins; D015800:Protozoan Proteins; D018749:RNA, Plant; D016053:RNA, Protozoan; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S; C084072:petD protein, cytochrome b(6)f complex; D045346:Cytochrome b6f Complex