Expression of recombinant truncated domains of mucus-binding (Mub) protein of Lactobacillus plantarum in soluble and biologically active form

Mucins amount to 70% of total proteins present in mammalian mucus and serve as important substrata for bacterial adhesion. In probiotic bacteria such as Lactobacillus plantarum, surface adhesion proteins mediate its adhesion to mucus and adhesion is pivotal in bi-directional host-microbe interactions. Mucus binding (Mub) proteins are a group of bacterial surface adhesion proteins that bind to mucin proteins. The structural framework and functional role of these proteins needs immediate attention but is poorly understood because of their large size, low yield and lack of highly purified protein. The lp_1643 gene of L. plantarum encodes a large Mub protein of 240 kDa and has six mucus binding (Mub) domains in tandem. In this study, the fragment of lp_1643 containing the last two domains with their preceding spacers herein referred to as Mubs5s6 was cloned and expressed in E. coli for probing its functional role in the adhesion of L. plantarum.