3.A.1.25.4
The biotin uptake system, BioMNY. The 3-d structure of the EcfS subunit, BioY, at 2.1Å resolution is known (Berntsson et al., 2012). BioY and ThiT from L. lactis show similar N-terminal structures for interaction with the ECF module but divergent C-terminal structures for substrate binding. BioY alone binds biotin but doesn''t transport it (Berntsson et al., 2012).  Ala-Arg-Ser and Ala-Arg-Gly signatures in BioN are probably coupling sites to the two BioM ATPase subunits (Neubauer et al., 2011Neubauer et al., 2011).