Binds bis-(3'-5') cyclic diguanylic acid (c-di-GMP), the ability to bind c-di-GMP is important for its function (PubMed:24942809). The central domain (GIL, residues 153-492) is sufficient for c-di-GMP binding. When the bcsEFG operon is disrupted in a cellulose-synthesizing strain (a strain K12 / W3110 derivative called AR3110 with a restored, functional bcsQ gene), cellulose is no longer made. Cellulose production is abolished in E.coli K12 / MG1655 and W3110 due to a premature stop codon in bcsQ (PubMed:24097954). Belongs to the BcsE family.