Probably a major component of the bacterial microcompartment (BMC) shell dedicated to ethanolamine degradation (Probable). Each homohexamer has a central pore with an opening of up to 8.6 Angstroms. A positively-charged funnel leads to the pore from each side of the hexamer; a phosphate or sulfate ion is found in the pore. The pore probably allows metabolite passage into and out of the BMC (PubMed:20851901, PubMed:20044574). Amine and polyamine degradation; ethanolamine degradation. Homohexamer with a central pore of up to 8.6 Angstroms diameter. The hexamers pack into a two-dimensional array (PubMed:20851901, PubMed:20044574). Interacts with EutQ (By similarity). Belongs to the bacterial microcompartments protein 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.