2CEC

2CEC is a four‑letter accession code used by the Protein Data Bank (PDB) to identify a specific three‑dimensional macromolecular structure. The entry was deposited in the PDB archive in 2004 and represents the high‑resolution x‑ray crystallographic structure of a bacterial DNA‑binding protein complex. The crystallographic study was performed at a resolution of 1.6 Å, providing detailed insights into the protein’s ligand‑binding pocket and DNA interaction surface. The asymmetric unit consists of two protein molecules arranged as a symmetric dimer in the crystal lattice, each bound to a short double‑stranded DNA duplex. Biochemical assays performed in parallel with the structural determination confirmed that the protein functions as a transcriptional regulator, modulating expression of genes involved in osmotic stress response.

The 2CEC structure has been cited in over 40 research articles, often as a reference model for comparative protein‑structure studies and for developing computational docking protocols. It is frequently used as a template for molecular dynamics simulations that explore the stability of protein–DNA interactions under different ionic conditions. The deposited atomic coordinates and associated refinement statistics are publicly available through the PDB database and have been incorporated into several structural biology teaching resources. Despite its specific biological context, the 2CEC entry serves as an exemplar of high‑quality crystal structures that facilitate a range of functional and evolutionary studies in the broader molecular biology community.