3.A.1.203.12
ABC transporter, BclA, of 586 aas and 6 TMSs in a 2 + 2 + 2 arrangement in the N-terminus and the ABC domain in the C-terminus.  It is a peptide transprter required for bacteroid differentiation.  It catalyzes import of peptides called nodule-specific cysteine-rich (NCR) peptides in the symbiotic nodule cells which house the bacteroids. NCR peptides are related to antimicrobial peptides of innate immunity, but they induce the endosymbionts into a differentiated, enlarged, and polyploid state (Guefrachi et al. 2015). BclA is required for the formation of differentiated and functional bacteroids in the nodules of the NCR peptide-producing Aeschynomene legumes. BclA catalyzes import of NCR peptides and provides protection against the antimicrobial activity of these peptides. Moreover, BclA can complement the role of the related BacA transporter of Sinorhizobium meliloti, which has a similar symbiotic function in the interaction with Medicago legumes (Guefrachi et al. 2015).