Functional characterisation of Lp_2714, an EAL-domain protein from Lactobacillus plantarum

► Lp_2714 is shown to lack critical residues involved in the metabolism of cyclic-di-GMP. ► Lp_2714 is shown to lack phosphodiesterase activity. ► A model is proposed in which Lp_2714 acts as a sensor for cyclic-di-GMP. ► Associated genes are proposed to be involved in polysaccharide synthesis. Bioinformatic analysis of lp_2714 from Lactobacillus plantarum WCFS1 demonstrates that it encodes an EAL-domain protein associated with a membrane targeting signal-sequence. Comparison of the predicted primary amino-acid sequence of Lp_2714 shows that it lacks critical catalytic residues and heterologous expression has determined that it does not encode a functional phosphodiesterase. We designate Lp_2714 as a class-3 EAL domain protein probably involved in regulating polysaccharide synthesis on the cell surface the cell.