CbiN is part of the active cobalt transport system involved in uptake of cobalt in to the cell involved with cobalamin biosynthesis (vitamin B12). It has been suggested that CbiN may function as the periplasmic binding protein component of the active cobalt transport system [1].

1: Characterization of the cobalamin (vitamin B12) biosynthetic genes of Salmonella typhimurium. Roth JR, Lawrence JG, Rubenfield M, Kieffer-Higgins S, Church GM; J Bacteriol 1993;175:3303-3316. PMID:8501034