Involved in the tonB-dependent energy-dependent transport of various receptor-bound substrates. Protects exbD from proteolytic degradation and functionally stabilizes tonB (By similarity). MMEEIKELIDYGIMGTLLFMSFVALAVGIERYLSIRSTKVENFKSKAQLEKELTKRLYIIATVASNAPYVGLLGTVLGILLTFYIIGEKGIVNTKEIMVGLALALKATALGLIVAIPSTILYNFLVRKVREKLLDWEAIHGECSSSHE exbB EXBB_AQUAE aq_1757 148 Biopolymer transport protein exbB