title: Maize high chlorophyll fluorescent 60 mutation is caused by an Ac disruption of the gene encoding the chloroplast ribosomal small subunit protein 17.
abstract: The maize mutation high chlorophyll fluorescence 60-muTable 1 (hcf60-m1), generated through Activator (Ac) tagging, has insufficient photosynthetic electron transport. Here we show that the Hcf60 gene encodes a protein with substantial amino acid similarity to plant plastid and bacterial ribosomal small subunit protein 17 (RPS17) proteins. The lack of detectable HCF60 transcripts in mutant leaves, and insertion of the transposed Ac element 17 bp upstream of the start of translation in the mutated locus, suggest that little if any RPS17 is produced. The mutant phenotype is consistent with reduced plastid translation. Seedling lethal hcf60-m1 plants display temperature and light-dependent chlorophyll deficiencies, a depletion of plastid rRNA pools, and few high-molecular-weight polysomal complexes. Growth under moderate light conditions (27 degrees C, 100 microE m-2 sec-1) allows for substantial chlorophyll accumulation in mutant leaves, yet the number of functional photosystem II complexes appears low. Nevertheless, the presence of a limited but intact C4 system indicates that some plastid translation occurs.
authors.affiliation: Department of Biochemistry and Genetics, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06511, USA. neil.schultes@po.state.ct.us
authors.forename: N P
authors.initials: NP
authors.lastname: Schultes
authors.forename: R J
authors.initials: RJ
authors.lastname: Sawers
authors.forename: T P
authors.initials: TP
authors.lastname: Brutnell
authors.forename: R W
authors.initials: RW
authors.lastname: Krueger
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins; D001419:Bacteria / Q000235:genetics; D001483:Base Sequence; D002736:Chloroplasts / Q000235:genetics* / Q000378:metabolism; D017343:Genes, Plant; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D010788:Photosynthesis; D010940:Plant Proteins / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D003313:Zea mays / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; C063050:RPS17 protein, Arabidopsis; D011994:Recombinant Proteins; D012269:Ribosomal Proteins