A component of the bacterial microcompartment (BMC) shell dedicated to ethanolamine degradation (PubMed:22428024, PubMed:27063436). Forms a hexagonal trimer with 3 small channels and a large central pore that has been seen in both open and closed forms and is probably used for gated transport into and out of the BMC (By similarity). Ethanolamine-binding by the small channels has been hypothesized to stabilize the EutL central pore in a closed (non-transporting) state. An open pore is thought to be large enough to transport ATP and/or cobalamin (By similarity). Expression of eutK, eutL, eutM, eutN, eutS (eutSMNLK) in E.coli leads to formation of a single BMC (PubMed:22428024, PubMed:27063436). Coexpression of eutQ with eutSMNLK permits E.coli to make cells with more than one mobile BMC, as is usual in vivo (PubMed:27063436). The ethanolamine (EA) catabolic bacterial microcompartment (BMC) probably concentrates low levels of ethanolamine catabolic enzymes, concentrates volatile reaction intermediates, keeps the level of toxic acetaldehyde low, generates enough acetyl-CoA to support cell growth, and maintains a pool of free coenzyme A (CoA) and NAD (Probable) (PubMed:16585748). Deletion of BMC genes (eutK, eutL, eutM) restores growth of eutD deletions, suggesting there are dedicated pools of coenzyme A (CoA) and NAD in the BMC (PubMed:23585538). Expression of the eut operon allows this bacteria to use ethanolamine as a carbon, nitrogen and energy source. It relies on cobalamin (vitamin B12) both as a cofactor for the ethanolamine ammonia-lyase (EAL) activity and to induce the operon (PubMed:3045078). EA enhances bacterial survival in macrophages in a concentration-dependent manner, suggesting it is an important nutrient during infection (PubMed:29531136). Amine and polyamine degradation; ethanolamine degradation. Homotrimerizes to form a pseudohexamer. Part of the 17-gene eut operon transcribed from a single promoter, induced by ethanolamine and adenosylcobalamin (AdoCbl, vitamin B12). Has 2 BMC domains which can evolve independently of each other. Not required for aerobic growth on ethanolamine (EA) supplemented with cobalamin (vitamin B12) (PubMed:10464203). A double eutL-eutK strain grows as well as wild-type on EA and cyanocobalamin, but a quadruple eutL-eutK eutM-eutN strain does not grow (PubMed:16291677). A non-polar deletion mutant grows on EA at pH 5.5 to pH 7.0 but not at pH 8.0 or pH 8.5, releases increased amounts of acetaldehyde on EA plus vitamin B12. Preventing acetaldehyde vapor loss allow growth up to pH 8.5 (PubMed:16585748). Artificial BMCs can be made in E.coli by expressing eutK, eutL, eutM, eutN, eutS (eutSMNLK) or eutS alone. Cargo proteins can be targeted to them and beta-galactosidase (lacZ) was active within the BMC, showing the BMC allows passage of substrate into the interior. This can lead to the development of tailored BMCs for specific metabolic reactions (PubMed:22428024). The addition of eutQ to the eutSMNLK construct results in biogenesis of multiple BMCs (PubMed:27063436). The need for a bacterial microcompartment in EA metabolism can be bypassed by increasing the levels of EAL and an acetaldehyde dehydrogenase (not necessarily EutE). Belongs to the EutL/PduB family.