May protect ethanolamine ammonia-lyase (EAL, eutB-eutC) from inhibition, may function in assembling the bacterial microcompartment and/or in refolding EAL, suggesting it may have chaperone activity. Amine and polyamine degradation; ethanolamine degradation. Belongs to the EutJ 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.