Reactivates suicidally inhibited ethanolamine ammonia-lyase (EAL), cyanocobalamin-inactivated EAL and O(2)-inactivated EAL; requires Mg(2+), ATP and adenosylcobalamin. Reactivation probably occurs by the ATP-dependent exchange of cobalamin. Amine and polyamine degradation; ethanolamine degradation. Ethanolamine ammonia-lyase (eutB-eutC) is no longer reactivated. Belongs to the EutA family. In strain MG1655 the eut operon is interrupted by the CPZ-55 prophage, encoding 9 genes situated between eutA and eutB, which are translated in the other direction. CPZ-55 may prevent expression of the eut operon in strain MG1655. Strain W3110 does not have this prophage element and should be able to express the operon.