Phosphate transport and arsenate resistance in the cyanobacterium Anabaena variabilis

Bioenergetics Studies of the Cyanobacterium Anabaena variabilis

A cell-free system exhibiting both photophosphorylation (P /2e = 1) and oxidative phosphoryla­ tion (P/O up to 0 .8 ) is described for the cyanobacterium Anabaena variabilis. NADH and N A D PH were found to be equally effective as electron donors for oxidative phosphorylation. Low concentrations of U H D B T , an inhibitor of the cytochrome blc complex of mitochondria and chloroplasts. were fou...

Molybdate transport and its effect on nitrogen utilization in the cyanobacterium Anabaena variabilis ATCC 29413.

Molybdenum is an essential component of the cofactors of many metalloenzymes including nitrate reductase and Mo-nitrogenase. The cyanobacterium Anabaena variabilis ATCC 29413 uses nitrate and atmospheric N2 as sources of nitrogen for growth. Two of the three nitrogenases in this strain are Mo-dependent enzymes, as is nitrate reductase; thus, transport of molybdate is important for growth of thi...

RNA processing of nitrogenase transcripts in the cyanobacterium Anabaena variabilis.

Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo-nitrogenase and the alternative V-nitrogenase, respectively, was studied by using a lacZ reporter. Despite evidence for a transcription start site just upstream of nifH1 and vnfH, promoter fragments that included ...

High-affinity vanadate transport system in the cyanobacterium Anabaena variabilis ATCC 29413.

High-affinity vanadate transport systems have not heretofore been identified in any organism. Anabaena variabilis, which can fix nitrogen by using an alternative V-dependent nitrogenase, transported vanadate well. The concentration of vanadate giving half-maximum V-nitrogenase activity when added to V-starved cells was about 3 x 10(-9) M. The genes for an ABC-type vanadate transport system, vup...

Potassium ion transport and electrogenesis in Anabaena variabilis.