Functional Overlap of hetP and hetZ in Regulation of Heterocyst Differentiation in Anabaena sp. Strain PCC 7120

Anabaena sp. strain PCC 7120 hetY gene influences heterocyst development.

The filamentous cyanobacterium Anabaena (Nostoc) sp. strain PCC 7120 responds to starvation for fixed nitrogen by producing a semiregular pattern of nitrogen-fixing cells called heterocysts. Overexpression of the hetY gene partially suppressed heterocyst formation, resulting in an abnormal heterocyst pattern. Inactivation of hetY increased the time required for heterocyst maturation and caused ...

Transcriptional regulation of the heterocyst patterning gene patA from Anabaena sp. strain PCC 7120.

The filamentous cyanobacterium Anabaena sp. strain PCC 7120 forms a periodic pattern of nitrogen-fixing heterocysts when grown in the absence of combined nitrogen. PatA is necessary for proper patterning of heterocysts along filaments. In this study, apparent transcriptional start points (tsps) were identified at nucleotides -305, -614, and -645 relative to the translational start site (-305, -...

Regulation by hetC of genes required for heterocyst differentiation and cell division in Anabaena sp. strain PCC 7120.

Unlike those of the wild-type strain, proheterocysts of the Anabaena sp. strain PCC 7120 hetC strain keep dividing. ftsZ, the most critical cell division gene, is up-regulated in hetC proheterocysts. Heterocyst differentiation genes hglD, hglE, patB, nifB, and xisA are no longer expressed in the hetC mutant. hetC also regulates the expression of patA, a pattern formation gene.

Strain PCC 7120 Heterocyst Distribution in Anabaena sp . Function of the HetN Factor Influencing Subcellular Localization

Clustered genes required for the synthesis of heterocyst envelope polysaccharide in Anabaena sp. strain PCC 7120.

As demonstrated with alr2835 (hepA) and alr2834 (hepC) mutants, heterocysts of Anabaena sp. strain PCC 7120, a filamentous cyanobacterium, must have an envelope polysaccharide layer (the Hep+ phenotype) to fix dinitrogen in an oxygen-containing milieu (the Fox+ phenotype). Transpositions presumptively responsible for a Fox- phenotype were localized in open reading frames (ORFs) near hepA and he...