4u6i
From Proteopedia
Crystal Structure of the EutL Microcompartment Shell Protein from Clostridium Perfringens Bound to Vitamin B12
Structural highlights
FunctionEUTL_CLOPE A component of the bacterial microcompartment (BMC) shell dedicated to ethanolamine degradation. May be involved in cofactor diffusion across the BMC (Probable). Cobalamin is covalently bound to 1 subunit of the trimer on the concave (lumenal) face in a closed pore conformation; whether this is physiologically relevant is unclear (PubMed:25484204). The closed form has 3 very narrow channels (1.3 Angstrom at their narrowest) per trimer lined by acidic and aromatic residues; 2 ethanolamine molecules can bind in each channel, on either side of the constriction. Does not bind acetate, ethanol or acetyl phosphate, all of which are small molecules involved in ethanolamine metabolism (PubMed:25752492). Ethanolamine-binding 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 (Probable).[1] [2] [3] [4] [5] Publication Abstract from PubMedThe EutL shell protein is a key component of the ethanolamine-utilization microcompartment, which serves to compartmentalize ethanolamine degradation in diverse bacteria. The apparent function of this shell protein is to facilitate the selective diffusion of large cofactor molecules between the cytoplasm and the lumen of the microcompartment. While EutL is implicated in molecular-transport phenomena, the details of its function, including the identity of its transport substrate, remain unknown. Here, the 2.1 A resolution X-ray crystal structure of a EutL shell protein bound to cobalamin (vitamin B12) is presented and the potential relevance of the observed protein-ligand interaction is briefly discussed. This work represents the first structure of a bacterial microcompartment shell protein bound to a potentially relevant cofactor molecule. Structure of a bacterial microcompartment shell protein bound to a cobalamin cofactor.,Thompson MC, Crowley CS, Kopstein J, Bobik TA, Yeates TO Acta Crystallogr F Struct Biol Commun. 2014 Dec 1;70(Pt 12):1584-90. doi:, 10.1107/S2053230X1402158X. Epub 2014 Nov 14. PMID:25484204[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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