D-a-Lysine mutase

Ethanolamine ammonia lyase, L-/ -lysine mutase, D-a-lysine mutase and ornithine mutase are representative of cobamide enzymes in which transfer of hydrogen occurs with cleavage of the C—N bond (Fig. 16). 

This cobalamin-dependent enzyme [EC 5.4.3.4], also called D-a-lysine mutase, catalyzes the interconversion of D-lysine and 2,5-diaminohexanoate. 

D-a-Lysine mutase and ornithine mutase catalyze the same type of reaction... 

Aminomutases. The enzymes L-p-lysine mutase (which is also D-a-lysine mutase) and D-omithine mutase catalyze the transfer of an co-amino group to an adjacent carbon atom (Table 16-1). Two proteins are needed for the reaction pyridoxal phosphate is required and is apparently directly involved in the amino group migration. In the P-lysine mutase the 6-amino group of L-P-lysine replaces the pro-S hydrogen at C-5 but with inversion at C-5 to yield (3S, 5S)-... 

MethylmalonylCoA mutase Glutamate mutase a-Methylene-glutarate mutase Dioldehydrase Glyceroldehydrase Ethanoldeaminase L-/3-lysine mutase D-a-lysine mutase Ribonucleotide reductase Methionine synthetase Methane synthetase Methyl transferase Acetate synthetase... 

Lysine 5,6-aminomutase (5,6-LAM) catalyzes the isomerization of D-lysine to 2,5-diaminohexanoic acid [180,181]. The mechanism proposed is analogous to that of D-ornithine amino mutase [228,229]. 5,6-LAM was predicted to be a base-off/His-on Bi2-dependent enzyme [230], as was recently conformed by the crystal structure [231]. 

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