title: alr0117, a two-component histidine kinase gene, is involved in heterocyst development in Anabaena sp. PCC 7120.
abstract: Anabaena sp. PCC 7120 was mutagenized by transposon Tn5-1087b, generating a mutant whose heterocysts lack the envelope polysaccharide layer. The transposon was located between nucleotides 342 and 343 of alr0117, a 918 bp gene encoding a histidine kinase for a two-component regulatory system. Complementation of the mutant with a DNA fragment containing alr0117 and targeted inactivation of the gene confirmed that alr0117 is involved in heterocyst development. RT-PCR showed that alr0117 was constitutively expressed in the presence or absence of a combined-nitrogen source. hepA and patB, the two genes turned on during wild-type heterocyst development, were no longer activated in an alr0117-null mutant. The two-component signal transduction system involving alr0117 may control the formation of the envelope polysaccharide layer and certain late events essential to the function of heterocysts.
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, PR China.
authors.forename: Degang
authors.initials: D
authors.lastname: Ning
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, PR China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D017033:Anabaena / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D017124:Conserved Sequence; D003434:Crossing Over, Genetic / Q000235:genetics; D017931:DNA Primers; D005798:Genes, Bacterial / Q000235:genetics*; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011494:Protein Kinases / Q000235:genetics*; D011994:Recombinant Proteins / Q000378:metabolism; D011995:Recombination, Genetic; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D011994:Recombinant Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase