Description of five mutants of the cyanobacterium Anabaena sp strain PCC 7120 affected in heterocyst differentiation and identification of the transposon-tagged genes.
When growing on N(2) as sole nitrogen source, the filamentous cyanobacterium Anabaena sp. PCC 7120 forms N(2) fixing heterocysts in a semi-regular pattern. To identify genes involved in heterocyst differentiation we characterised five transposon-generated mutants that were not able to form mature heterocysts. After recovering the transposon together with the flanking region of the Anabaena chromosome the affected genes were identified. Four of the genes could be involved in formation of the heterocyst-specific envelope: alr2887, encoding a probable outer membrane efflux protein, alr3698, a glycosyl transferase, all4388, a putative periplasmic polysaccharide export protein and alr5357, the formerly described gene hglB/hetM, encoding a fatty-acid synthetase. Another gene, all0049/mutS2, may be important in one of the genome rearrangements that occur during heterocyst differentiation. By transcriptional fusion to reporter genes luxAB differential expression of alr2887, alr3698 and alr5357 could be monitored during heterocyst differentiation.
Maldener
Iris
I
Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, 93040 Regensburg, Germany. iris.maldener@biologie.uni-regensurg.de
Hannus
Stefan
S
Kammerer
Monika
M
D000595:Amino Acid Sequence; D017033:Anabaena / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004251:DNA Transposable Elements; D015964:Gene Expression Regulation, Bacterial; D016695:Glycosyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation / Q000235:genetics*; D010641:Phenotype; D011134:Polysaccharides / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004251:DNA Transposable Elements; D011134:Polysaccharides; D016695:Glycosyltransferases; D009584:Nitrogen