Alternative Chromophore Binding Sites in Non-Covalent Fluorescent Complexes of Bacterial Lipocalin

Abstract

The three-dimensional structure of DiB3, a fluorescent non-covalent complex of a genetically engineered variant of the bacterial protein lipocalin Blc with a synthetic GFP-like chromophore M739, was determined by the calculation method of molecular mechanics. Compared to the crystal structure of the related DiB1 complex, an alternative binding site for the M739 chromophore was found in the structure of the DiB3 complex.