1.4.4.2	glycine + [glycine-cleavage complex H protein]-N6-lipoyl-L-lysine = [glycine-cleavage complex H protein]-S-aminomethyl-N6-dihydrolipoyl-L-lysine + CO2	mechanism	
1.4.4.2	glycine + [glycine-cleavage complex H protein]-N6-lipoyl-L-lysine = [glycine-cleavage complex H protein]-S-aminomethyl-N6-dihydrolipoyl-L-lysine + CO2	H-protein ping-pong mechanism	
1.4.4.2	glycine + [glycine-cleavage complex H protein]-N6-lipoyl-L-lysine = [glycine-cleavage complex H protein]-S-aminomethyl-N6-dihydrolipoyl-L-lysine + CO2	sequential random bi bi mechanism in which no abortive dead end complex is formed	
1.4.4.2	glycine + [glycine-cleavage complex H protein]-N6-lipoyl-L-lysine = [glycine-cleavage complex H protein]-S-aminomethyl-N6-dihydrolipoyl-L-lysine + CO2	mechanism of the GLDC-catalyzed reaction, detailed overview. GLDC is an unusual PLP-containing alpha-amino acid decarboxylase that removes carbon dioxide from the glycine substrate without releasing the expected amine (methylamine, a metabolic precursor of toxic formaldehyde) as a product. In an unusual decarboxylation mechanism, the resulting aminomethyl moiety is instead transferred to an accessory H-protein. (1) H-Protein is not required for glycine decarboxylation but, instead, is required for the release of the aminomethyl moiety from the quinonoid adduct. (2) Glycine decarboxylation is reversible and presumably proceeds through a stable quinonoid intermediate. (3) The physiological product of glycine decarboxylation is H-protein-S-aminomethyl dihydrolipoyllysine and not methylamine (in the absence of H-protein, the aminomethyl moiety remains as a quinonoid adduct)