Serine pyruvate

Branched chain aminotransferase Gamma-aminobutyrate aminotransferase CO-Amino acid pyruvate aminotransferase Tyrosine aminotransferase Serine pyruvate aminotransferase... 

This reaction can be considered to be the result of the coupling tryptophanL + h2o = indole + serine and serine = pyruvate + ammonia, and so it involves one constraint. 

Some acetogenic bacteria, which convert CO2 to acetic acid, form pyruvate for synthesis of carbohydrates, etc., by formation of formaldehyde and conversion of the latter to glycine by reversal of the PLP and lipoic acid-dependent glycine decarboxylase, a 4-protein system. The glycine is then converted to serine, pyruvate, oxaloacetate, etc. Propose a detailed pathway for this sequence. 

There are three known pathways for the catabolism of serine, pyruvate + H2O... 

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