title: A novel genetic organization: the leuA-rpoD1 locus in the cyanobacterium Microcystis aeruginosa K-81.
abstract: We cloned and sequenced the region upstream of rpoD1, which encodes a principal sigma factor in the cyanobacterium Microcystis aeruginosa K-81. An open reading frame (orf1, 1599 bp) was discovered, the deduced amino-acid sequence of which (533 aa, 58, 016 Da) exhibits homology to another bacterial leuA gene product, 2-isopropylmalate synthase. The leuA (orf1) gene specifically complemented an E. coli leuA mutant. The 5'-upstream region of leuA did not contain possible leader peptide or stem-loop structures for attenuation. These findings indicate that the genetic structure of the leuA-rpoD1 locus in M. aeruginosa K-81 significantly differs from those of known leuA and rpoD loci found in other bacteria.
authors.affiliation: Laboratory of Molecular Microbiology, School of Agriculture, Ibaraki University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Asayama
authors.forename: M
authors.initials: M
authors.lastname: Kabasawa
authors.forename: M
authors.initials: M
authors.lastname: Shirai
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D007535:Isomerases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D046931:Microcystis / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012045:Regulatory Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases; C032241:isopropylmalate isomerase; D007535:Isomerases