Are alpha-ketoglutarate and glutamate involved in all transamination reactions? Is it true that for all biochemical transamination reactions, that alpha-ketoglutarate and glutamate serve as the amino group acceptor and donor, respectively? If this is true, then is it safe to assume that alpha-ketoglutarate is necessary for every transamination reaction?

The major transaminases such as the aspartate transaminase and alanine transaminase involve the glutamate α-ketoglutarate interconversion. Even the GABA aminotransferase employs glutamate/α-ketoglutarate. It seems that all transaminases use glutamate/α-ketoglutarate; in fact most of them do.

These are a few that don't:

* Beta-alanine--pyruvate transaminase.
* Tryptophan--phenylpyruvate transaminase.
* Pyridoxamine--pyruvate transaminase.
* Aminolevulinate aminotransferase.
* Serine--pyruvate transaminase.
* Aspartate--prephenate aminotransferase.



And a few more (see here). Most of these are present in plants.