Structures of the inducer-binding domain of pentachlorophenol-degrading gene regulator PcpR from Sphingobium chlorophenolicum.

ABSTRACT: PcpR is a LysR-type transcription factor from Sphingobium chlorophenolicum L-1 that is responsible for the activation of several genes involved in polychlorophenol degradation. PcpR responds to several polychlorophenols in vivo. Here, we report the crystal structures of the inducer-binding domain of PcpR in the apo-form and binary complexes with pentachlorophenol (PCP) and 2,4,6-trichlorophenol (2,4,6-TCP). Both X-ray crystal structures and isothermal titration calorimetry data indicated the association of two PCP molecules per PcpR, but only one 2,4,6-TCP molecule. The hydrophobic nature and hydrogen bonds of one binding cavity allowed the tight association of both PCP (Kd = 110 nM) and 2,4,6-TCP (Kd = 22.8 nM). However, the other cavity was unique to PCP with much weaker affinity (Kd = 7

SUBMITTER: Hayes RP 

PROVIDER: S-EPMC4264193 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature