A point mutation in the gene encoding the Rubisco large subunit interferes with holoenzyme assembly.
Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), a key enzyme of photosynthetic CO2 fixation, is composed of 8 large and 8 small subunits. The Rubisco-deficient Nicotiana tabacum mutant Sp25 is able to synthesize the peptides for both subunits but does not contain any active holoenzyme. The phenotype is maternally inherited and thus caused by a mutation in the chloroplast genome, which also encodes the Rubisco large subunit. A comparison of the nucleotide sequences of the large subunit gene of the Sp25 mutant with that of the wild-type tobacco revealed a single nucleotide change in the Sp25 mutant. This resulted in an amino acid substitution at Gly-322, which was replaced by serine.
Shikanai
T
T
Plant Molecular Physiology Lab., RITE, Kyoto, Japan.
Foyer
C H
CH
Dulieu
H
H
Parry
M A
MA
Yokota
A
A
D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D018742:DNA, Chloroplast / Q000235:genetics; D017343:Genes, Plant; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010947:Plants, Toxic; D017354:Point Mutation; D011487:Protein Conformation; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics*; D013329:Structure-Activity Relationship; D014026:Nicotiana / Q000235:genetics*
D017931:DNA Primers; D018742:DNA, Chloroplast; D046911:Macromolecular Substances; D012273:Ribulose-Bisphosphate Carboxylase