Hetero-oligomeric cell wall channels (porins) of Nocardia farcinica

► The cell wall channel of the mycolata Nocardia farcinica ATTC 3318 was subjected to Edman-degradation. ► Based on BLAST analysis six genes were identified in genome of N. farcinica IFM 10152 coding for cell wall channel. ► The six genes are organized in tandems of two genes separated only by few base pairs from one another. ► The cell wall channel of N. farcinica ATTC 3318 is formed by a heteropolymer of two subunits NfpA and NfpB. ► NfpA and NfpB form together a channel structurally related to MspA of Mycobacterium smegmatis.