title: CalA, a cyAbrB protein, binds to the upstream region of ftsZ and is down-regulated in heterocysts in Anabaena sp. PCC 7120.
abstract: A protein of cyAbrB family of regulators, Alr0946 (CalA), was identified by DNA affinity chromatography using DNA fragments from the promoter region of ftsZ in Anabaena/Nostoc sp. PCC 7120. Electrophoretic mobility shift assays showed that the protein could bind to upstream regions of ftsZ (as biotin-labeled DNA fragments) and that the binding was inhibited by the same DNA fragments and a fragment upstream of hetC but not by 3 fragments upstream of glnA, hetR or ntcA. Both transcriptional fusion with gfp (green fluorescence protein) and Western blot analysis indicated that the expression of calA was down-regulated in heterocysts relative to vegetative cells. An insertional mutant of calA could not be completely segregated. Over-expression of calA in Anabaena/Nostoc caused no change in growth, heterocyst differentiation or expression of ftsZ. CalA as a DNA-binding protein is essential for the growth of Anabaena/Nostoc and may be required for the expression of ftsZ in vegetative cells.
authors.affiliation: The State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, Hubei, China.
authors.forename: Dongli
authors.initials: D
authors.lastname: He
authors.forename: Xudong
authors.initials: X
authors.lastname: Xu
mesh_terms: D017033:Anabaena / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003300:Copper / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial; D049452:Green Fluorescent Proteins / Q000235:genetics; D046937:Nostoc / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C071525:FtsZ protein, Bacteria; D049452:Green Fluorescent Proteins; D003300:Copper