Journal
PHOTOSYNTHESIS RESEARCH
Volume 123, Issue 2, Pages 129-139Publisher
SPRINGER
DOI: 10.1007/s11120-014-0044-2
Keywords
Glutamate synthase; Ferredoxin; Protein/protein interactions; FMN; Iron-sulfur clusters
Categories
Funding
- Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy [DE-FG03-99ER20346]
- Ministerio de Economia y Competitividad of Spain [BFU2010-15708]
- European Regional Funds (FEDER)
- Texas Tech University Graduate School
Ask authors/readers for more resources
It had been proposed that a loop, typically containing 26 or 27 amino acids, which is only present in monomeric, ferredoxin-dependent, plant-type glutamate synthases and is absent from the catalytic alpha-subunits of both NADPH-dependent, heterodimeric glutamate synthases found in non-photosynthetic bacteria and NADH-dependent heterodimeric cyanobacterial glutamate synthases, plays a key role in productive binding of ferredoxin to the plant-type enzymes. Site-directed mutagenesis has been used to delete the entire 27 amino acid-long loop in the ferredoxin-dependent glutamate synthase from the cyanobacterium Synechocystis sp. PCC 6803. The specific activity of the resulting loopless variant of this glutamate synthase, when reduced ferredoxin serves as the electron donor, is actually higher than that of the wild-type enzyme, suggesting that this loop is not absolutely essential for efficient electron transfer from reduced ferredoxin to the enzyme. These results are consistent with the results of an in-silico study that suggests that the loop is unlikely to interact directly with ferredoxin in the energetically most favorable model of a 1:1 complex of ferredoxin with the wild-type enzyme.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available