PdeL is a c-di-GMP-specific phosphodiesterase consisting of an N-terminal LuxR-like DNA-binding domain and a C-terminal EAL domain that is required for phosphodiesterase activity . The isolated EAL domain of the enzyme is in a fast monomer-dimer equilibrium. Only the dimeric form of PdeL has phosphodiesterase activity, and substrate binding increases dimerization affinity .
Crystal structures of the EAL domain alone and in various complexes have been solved, showing structural coupling between the dimer interface and the catalytic site .
A screen for suppressors of the motility defect of a |FRAME: EG12252 ΔpdeH| mutant identified activating mutations in E. coli's alternative c-di-GMP phosphodiesterases (PDEs), including PdeL. This supports a model whereby the signaling specificity of PDEs is the result of environmental signals required for their activation. Suppressor mutations in pdeL consisted of point mutations that are located within its catalytic EAL domain and resulted in higher levels of PdeL protein, increased enzymatic activity, reduced levels of intracellular c-di-GMP, and increased swimming motility .
pdeL expression is autoregulated . PdeL can be considered a molecule with enzymatic and regulatory capabilities due to its phosphodiesterase activity and its capability to bind to its own promoter region and stimulate its expression in response to c-di-GMP 
PdeL: phosphodiesterase with N-terminal LuxR domain 
|Connectivity class:||Local Regulator|
|Length:||1089 bp / 362 aa|
|TU(s) encoding the TF:||
|Functional conformation||Function||Promoter||Sigma factor||Central Rel-Pos||Distance to first Gene||Genes||Sequence||LeftPos||RightPos||Evidence (Confirmed, Strong, Weak)||References|
|331672||331695||[BPP], [GEA], [IHBCE]|||
|Evolutionary conservation of regulatory elements|
 Reinders A., Hee CS., Ozaki S., Mazur A., Boehm A., Schirmer T., Jenal U., 2016, Expression and Genetic Activation of Cyclic Di-GMP-Specific Phosphodiesterases in Escherichia coli., J Bacteriol. 198(3):448-62
 Schmidt AJ., Ryjenkov DA., Gomelsky M., 2005, The Ubiquitous Protein Domain EAL Is a Cyclic Diguanylate-Specific Phosphodiesterase: Enzymatically Active and Inactive EAL Domains., J Bacteriol. 187(14):4774-81
 Sundriyal A., Massa C., Samoray D., Zehender F., Sharpe T., Jenal U., Schirmer T., 2014, Inherent regulation of EAL domain-catalyzed hydrolysis of second messenger cyclic di-GMP., J Biol Chem. 289(10):6978-90
 Hengge R., Galperin MY., Ghigo JM., Gomelsky M., Green J., Hughes KT., Jenal U., Landini P., 2015, Systematic Nomenclature for GGDEF and EAL Domain-Containing Cyclic Di-GMP Turnover Proteins of Escherichia coli., J Bacteriol. 198(1):7-11