title: Cloning and characterization of the RNA polymerase alpha-subunit operon of Chlamydia trachomatis.
abstract: We have cloned the chlamydial operon that encodes the initiation factor IF1, the ribosomal proteins L36, S13, and S11, and the alpha subunit of RNA polymerase. The genes for S11 and alpha are closely linked in Escherichia coli, Bacillus subtilis, and plant chloroplast genomes, and this arrangement is conserved in Chlamydia spp. The S11 ribosomal protein gene potentially encodes a protein of 125 amino acids with 41 to 42% identity over its entire length to its E. coli and B. subtilis homologs; the gene encoding the alpha subunit specifies a protein of 322 amino acids with 25 to 30% identity over its entire length to its E. coli and B. subtilis homologs. In a T7-based expression system in E. coli, the chlamydial alpha gene directed the synthesis of a 36-kDa protein. Mapping of the chlamydial mRNA transcript by RNase protection studies and by a combination of reverse transcription and the polymerase chain reaction demonstrates that IF1, L36, S13, S11, and alpha are transcribed as a polycistronic transcript.
authors.affiliation: Department of Microbiology and Immunology, University of California, San Francisco 94143.
authors.forename: M
authors.initials: M
authors.lastname: Tan
authors.forename: R
authors.initials: R
authors.lastname: Klein
authors.forename: R
authors.initials: R
authors.lastname: Grant
authors.forename: D
authors.initials: D
authors.lastname: Ganem
authors.forename: J
authors.initials: J
authors.lastname: Engel
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics; D001483:Base Sequence; D002692:Chlamydia trachomatis / Q000201:enzymology* / Q000235:genetics*; D002736:Chloroplasts / Q000201:enzymology; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics; D017931:DNA Primers; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis* / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D015977:Eukaryotic Initiation Factor-1 / Q000235:genetics; D005798:Genes, Bacterial; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009876:Operon; D010944:Plants / Q000235:genetics; D015183:Restriction Mapping; D012269:Ribosomal Proteins / Q000235:genetics; D012486:Salmonella typhimurium / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D003062:Codon; D017931:DNA Primers; D029968:Escherichia coli Proteins; D015977:Eukaryotic Initiation Factor-1; D046911:Macromolecular Substances; D012269:Ribosomal Proteins; C045454:ribosomal protein S11; C512838:rpsM protein, E coli; D012321:DNA-Directed RNA Polymerases