Glutamine synthetase gene evolution: a good molecular clock.

Glutamine synthetase gene evolution in bacteria.

The evolution of the prokaryotic glutamine synthase (GS) genes, namely the GSI and GSII isoforms, has been investigated using the second codon positions, which have previously proven to behave as a good molecular clock. Our data confirm the early divergence between prokaryotic and eukaryotic GSII before the splitting between plants and animals. The phylogenetic tree of the GSI isoforms shows Ar...

Biochemical and molecular analysis of glutamine synthetase gene in brassica napus L.

Evolution of glutamine synthetase in vertebrates: multiple glutamine synthetase genes expressed in rainbow trout (Oncorhynchus mykiss).

Glutamine synthetase (GSase) is a key enzyme in nitrogen metabolism and encoded by a single gene in mammals. Using PCR cloning techniques, including RT-PCR from total RNA and PCR from a cDNA library, we find evidence of four expressed GSase mRNAs for the tetraploid rainbow trout. For two of these mRNAs (Onmy-GS01, -GS02) we characterize the full-length coding regions, and for two others (Onmy-G...

Regulation of synthesis of glutamine synthetase by adenylylated glutamine synthetase.

We have examined three mutants of Klebsiella aerogenes whose genetic lesions (glnB, glnD, and glnE) are in loci unlinked to the structural gene for glutamine sythetase (glnA) and in which the control of both the level and state of adenylylation of glutamine synthetase is altered. Each mutation alters a different component of the adenylylation system of glutamine synthetase [L-glutamate:ammonia ...

Molecular Evolution of Glutamine Synthetase Ii and Iii in the Chromalveolates(1).

Glutamine synthetase (GS) is encoded by three distinct gene families (GSI, GSII, and GSIII) that are broadly distributed among the three domains of life. Previous studies established that GSII and GSIII isoenzymes were expressed in diatoms; however, less is known about the distribution and evolution of the gene families in other chromalveolate lineages. Thus, GSII cDNA sequences were isolated f...