1.S.2. The Bacterial Microcompartment Shell/Pore-forming Protein-2 (BMC-SP2) Family
In contrast to the BMC-SP1 family which consists of small proteins of about 100 aas, the BMC-SP2 family consists of proteins of somewhat greater than 200 aas and are non-homologous to the BMC-SP1 proteins. However, they contribute to shell formation, sometimes in the same BMC shell as a BMC-SP1 protein as in the ethanolamine utilizing (Eut) BMC of E. coli, and both types of shell proteins form pores (Takenoya et al. 2010). In contrast to EutL (BMC-SP1), the pore of EutM (BMC-SP2) appears to be positively carged, indicating specificity for different solutes. Moreover, only the pore of EutL can be triggered to open by exposure to zinc ions (Takenoya et al. 2010).
The pore-forming shell protein, EutL, of 219 aas, of the bacterial ethanolamine-utilizing microcompartment (BMC) (Takenoya et al. 2010).
EutL of E. coli
PduB shell protein of 270 aas of a propanediol utilization polyhedral body
PduB of Salmonella paratyphi C
Uncharacterized DUF692 domain-containing protein of 286 aa
UP of Nocardia grenadensis