title: Nucleotide sequence, promoter analysis, and linkage mapping of the unusually organized operon encoding ribosomal proteins S7 and S12 in maize chloroplast.
abstract: The nucleotide sequence of the operon encoding maize chloroplast ribosomal protein genes S7 and S12 and the promoter activity of a chimeric construct of the -10/-35 sequence of this operon (attached to a promoterless chloramphenicol acetyltransferase gene) have been determined. This operon occurs in the chloroplast genome divided in two parts: part A contains exon 1 of rpS12 (encoding the N-terminal 38 amino acid residues), whereas part B has the following structure: promoter-rpS12 (exon 2 + intron + exon 3)-spacer-rpS7-terminator. Part A is located at the approximate coordinate position 41000, whereas two copies of part B are located at two distant locations in the genome at coordinate positions 18700 and 120200. This unusual organization of the S12 operon in maize (a monocot plant) is similar to that reported in a dicot and a lower plant. The deduced amino acid sequence of maize chloroplast S7 shows 43, 38, 71, and 85% and of S12 shows 66, 72, 91 and 90% sequence identity to the corresponding sequences of Escherichia coli, Euglena gracilis, Marchantia polymorpha, and Nicotiana tabacum, respectively. The promoter upstream of rpS12 (part B) is transcriptionally active in E. coli.
authors.affiliation: Max-Planck-Institut für Molekulare Genetik, Abteilung Wittmann, Berlin, West Germany.
authors.forename: K
authors.initials: K
authors.lastname: Giese
authors.forename: A R
authors.initials: AR
authors.lastname: Subramanian
authors.forename: I M
authors.initials: IM
authors.lastname: Larrinua
authors.forename: L
authors.initials: L
authors.lastname: Bogorad
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002736:Chloroplasts / Q000378:metabolism*; D004262:DNA Restriction Enzymes; D008040:Genetic Linkage; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009876:Operon; D010944:Plants / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012269:Ribosomal Proteins / Q000235:genetics*; D003313:Zea mays / Q000235:genetics / Q000378:metabolism
chemical_list: D012269:Ribosomal Proteins; C034212:ribosomal protein S12; C037442:ribosomal protein S7; D004262:DNA Restriction Enzymes