Clustered genes required for the synthesis of heterocyst envelope polysaccharide in Anabaena sp strain PCC 7120
Clustered genes required for the synthesis of heterocyst envelope polysaccharide in Anabaena sp strain PCC 7120
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DOI：
10.1128/jb.187.3.1114-1123.2005
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发表时间：
2005-02-01
影响因子：
3.2
通讯作者：
Tabata, S
中科院分区：
文献类型：
--
作者：
Huang, G;Qing, F;Tabata, S
正如 alr2835 (hepA) 和 alr2834 (hepC) 突变体所证明的，鱼腥藻杂胞。 PCC 7120 菌株是一种丝状蓝藻，必须具有包膜多糖层（Hep(+) 表型）才能将二氮固定在含氧环境（Fox(+) 表型）中。推测导致 Fox(-) 表型的转座位于 hepA 和 hepC 附近的开放阅读框 (ORF) 中。这九个 ORF 中每一个的突变都由仅带有单个完整 ORF 的克隆来补充。发现九个突变体的异形囊缺乏包膜多糖层。 alr2832 和 alr2840 突变的互补可能是重组的结果。然而，alr2825、alr2827、alr2831、alr2833、alr2837、air2839 和 alr2841 与 hepA 和 hepC 一样，是 Hep(+) Fox(+) 表型所必需的。
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, air2839, and alr2841, like hepA and hepC, are required for a Hep(+) Fox(+) phenotype.