title: adg2-1 represents a missense mutation in the ADPG pyrophosphorylase large subunit gene of Arabidopsis thaliana.
abstract: Arabidopsis mutants affecting ADPG pyrophosphorylase (ADGase) activity can be divided into two complementation groups, adg1 and adg2. Previous biochemical studies of adg2-1 mutant indicated that mutant plants do not accumulate ADGase large subunit protein and that ADGase small subunits assemble as homotetramers. This suggested that the ADG2 gene may encode the large subunit of ADGase. In this paper, it is shown that adg2-1 mutant plants accumulate near wild-type levels of transcripts encoding both the large and small subunits of ADGase. However, by RFLP analysis and complementation of adg2-1 with the ADGase large subunit gene, we show that the adg2-1 mutant does represent a mutation of the ADGase large subunit gene. Sequence analysis of the adg2-1 allele revealed a missense mutation. The results therefore suggest either that the missense mutation affects the stability of the ADGase large subunit protein or that it prevents assembly of the large subunit into holoenzyme.
authors.affiliation: Department of Botany, National Taiwan University, Taipei, Taiwan.
authors.forename: S M
authors.initials: SM
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Chu
authors.forename: W L
authors.initials: WL
authors.lastname: Lue
authors.forename: T S
authors.initials: TS
authors.lastname: Yu
authors.forename: K
authors.initials: K
authors.lastname: Eimert
authors.forename: J
authors.initials: J
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins; D002736:Chloroplasts / Q000201:enzymology; D018076:DNA, Complementary / Q000235:genetics; D004795:Enzyme Stability; D017343:Genes, Plant; D005816:Genetic Complementation Test; D015698:Genomic Library; D051599:Glucose-1-Phosphate Adenylyltransferase; D008969:Molecular Sequence Data; D009154:Mutation; D009713:Nucleotidyltransferases / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D009713:Nucleotidyltransferases; C496715:ADP-glucose pyrophosphorylase, Arabidopsis; D051599:Glucose-1-Phosphate Adenylyltransferase