CHASE8 is a conserved periplasmic sensor domain found in histidine kinases, diguanylate cyclases/phosphodiesterases and methyl-accepting chemotaxis proteins, including the diguanylate cyclase DgcN (YfiN) that regulates biofilm formation and motility in Escherichia coli [1, 2]. In Pseudomonas aeruginosa, CHASE8 is the sensor domain in the diguanylate cyclase TpbB that regulates biofilm formation [3] by controlling the levels of extracellular DNA [4].

1: Connecting quorum sensing, c-di-GMP, pel polysaccharide, and biofilm formation in Pseudomonas aeruginosa through tyrosine phosphatase TpbA (PA3885). Ueda A, Wood TK; PLoS Pathog. 2009;5:e1000483. PMID:19543378

2: Systematic Nomenclature for GGDEF and EAL Domain-Containing Cyclic Di-GMP Turnover Proteins of Escherichia coli. Hengge R, Galperin MY, Ghigo JM, Gomelsky M, Green J, Hughes KT, Jenal U, Landini P; J Bacteriol. 2015;198:7-11. PMID:26148715

3: GGDEF proteins YeaI, YedQ, and YfiN reduce early biofilm formation and swimming motility in Escherichia coli. Sanchez-Torres V, Hu H, Wood TK; Appl Microbiol Biotechnol. 2011;90:651-658. PMID:21181144

4: Tyrosine Phosphatase TpbA of Pseudomonas aeruginosa Controls Extracellular DNA via Cyclic Diguanylic Acid Concentrations. Ueda A, Wood TK; Environ Microbiol. 2010;2:449-455. PMID:21552365