title: Clustered genes required for the synthesis of heterocyst envelope polysaccharide in Anabaena sp. strain PCC 7120.
abstract: 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 hepC. A mutation in each of nine of these ORFs was complemented by a clone bearing only that single, intact ORF. Heterocysts of the nine mutants were found to lack an envelope polysaccharide layer. Complementation of mutations in alr2832 and alr2840 may have resulted from recombination. However, alr2825, alr2827, alr2831, alr2833, alr2837, alr2839, and alr2841, like hepA and hepC, are required for a Hep+ Fox+ phenotype.
authors.affiliation: MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824-1312, USA.
authors.forename: Guocun
authors.initials: G
authors.lastname: Huang
authors.forename: Qing
authors.initials: Q
authors.lastname: Fan
authors.forename: Sigal
authors.initials: S
authors.lastname: Lechno-Yossef
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Wojciuch
authors.forename: C Peter
authors.initials: CP
authors.lastname: Wolk
authors.forename: Takakazu
authors.initials: T
authors.lastname: Kaneko
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
mesh_terms: D017033:Anabaena / Q000235:genetics* / Q000254:growth & development; D017931:DNA Primers; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D005810:Multigene Family / Q000235:genetics*; D016254:Mutagenesis, Insertional; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D011135:Polysaccharides, Bacterial / Q000235:genetics*
chemical_list: D017931:DNA Primers; D011135:Polysaccharides, Bacterial