A Previously Unrecognized Step in Pentachlorophenol Degradation in; Sphingobium chlorophenolicum; Is Catalyzed by Tetrachlorobenzoquinone Reductase (PcpD) Journal Article uri icon

Overview

abstract

  • ABSTRACT; ; The first step in the pentachlorophenol (PCP) degradation pathway in; Sphingobium chlorophenolicum; has been believed for more than a decade to be conversion of PCP to tetrachlorohydroquinone. We show here that PCP is actually converted to tetrachlorobenzoquinone, which is subsequently reduced to tetrachlorohydroquinone by PcpD, a protein that had previously been suggested to be a PCP hydroxylase reductase.; pcpD; is immediately downstream of; pcpB; , the gene encoding PCP hydroxylase (PCP monooxygenase). Expression of PcpD is induced in the presence of PCP. A mutant strain lacking functional PcpD has an impaired ability to remove PCP from the medium. In contrast, the mutant strain removes tetrachlorophenol from the medium at the same rate as does the wild-type strain. These data suggest that PcpD catalyzes a step necessary for degradation of PCP, but not for degradation of tetrachlorophenol. Based upon the known mechanisms of flavin monooxygenases such as PCP hydroxylase, hydroxylation of PCP should produce tetrachlorobenzoquinone, while hydroxylation of tetrachlorophenol should produce tetrachlorohydroquinone. Thus, we proposed and verified experimentally that PcpD is a tetrachlorobenzoquinone reductase that catalyzes the NADPH-dependent reduction of tetrachlorobenzoquinone to tetrachlorohydroquinone.;

publication date

  • January 1, 2003

Date in CU Experts

  • April 25, 2014 7:34 AM

Full Author List

  • Dai M; Rogers JB; Warner JR; Copley SD

author count

  • 4

Other Profiles

International Standard Serial Number (ISSN)

  • 0021-9193

Electronic International Standard Serial Number (EISSN)

  • 1098-5530

Additional Document Info

start page

  • 302

end page

  • 310

volume

  • 185

issue

  • 1