Open AccessThe activation of glutamine synthetase from the cyanobacterium Anabaena cylindrica by thioredoxin
Author(s) -
Papen Hans,
Bothe Hermann
Publication year - 1984
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1984.tb01032.x
Subject(s) - glutamine synthetase , thioredoxin , heterocyst , isocitrate dehydrogenase , biochemistry , anabaena , cyanobacteria , enzyme , biology , malate dehydrogenase , glutamine , spinach , glutamine amidotransferase , dehydrogenase , bacteria , genetics , amino acid
The present communication defines the conditions under which thioredoxin activates glutamine synthetase from Anabaena cylindrica . Effects are obtained at pH values around neutrality, and the activation is affected by Mg 2+ in the assays. The thioredoxin systems from A. cylindrica and spinach are functionally interchangeable in the activation of glutamine synthetase. The enzyme is efficiently activated by thioredoxin m and also by thioredoxin f , but at much higher concentrations. Thioredoxin m has previously been shown to activate NADPH‐dependent malate dehydrogenase and isocitrate dehydrogenase from cyanobacteria. It is speculated that thioredoxin m plays a role in the differentiation of vegetative cells to heterocysts.