The explosive-degrading cytochrome P450 XplA: Biochemistry, structural features and prospects for bioremediation

TY - JOUR

T1 - The explosive-degrading cytochrome P450 XplA: Biochemistry, structural features and prospects for bioremediation

AU - Rylott, Elizabeth L.

AU - Jackson, Rosamond G.

AU - Sabbadin, Federico

AU - Seth-Smith, Helena M. B.

AU - Edwards, James

AU - Chong, Chun Shiong

AU - Strand, Stuart E.

AU - Grogan, Gideon

AU - Bruce, Neil C.

PY - 2011/1

Y1 - 2011/1

N2 - XplA is a cytochrome P450 that mediates the microbial metabolism of the military explosive hexahydro1,3,5-trinitro-1,3,5-triazine (RDX). It has an unusual structural organisation comprising a heme domain that is fused to its flavodoxin redox partner. XplA along with its partnering reductase XplB are plasmid encoded and the gene xplA has now been found in divergent genera across the globe with near sequence identity. Importantly, it has only been detected at explosives contaminated sites suggesting rapid dissemination of this novel catabolic activity, possibly within the 50-year period since the introduction of RDX into the environment. The X-ray structure of XplA-heme has been solved, providing fundamental information on the heme binding site. Interestingly, oxygen is not required for the degradation of RDX, but its presence determines the final degradation products, demonstrating that the degradation chemistry is flexible with both anaerobic and aerobic pathways resulting in the release of nitrite from the substrate. Transgenic plants expressing xplA are able to remove saturating levels of RDX from soil leachate and may provide a low cost sustainable remediation strategy for contaminated military sites. (C) 2010 Elsevier B.V. All rights reserved.

AB - XplA is a cytochrome P450 that mediates the microbial metabolism of the military explosive hexahydro1,3,5-trinitro-1,3,5-triazine (RDX). It has an unusual structural organisation comprising a heme domain that is fused to its flavodoxin redox partner. XplA along with its partnering reductase XplB are plasmid encoded and the gene xplA has now been found in divergent genera across the globe with near sequence identity. Importantly, it has only been detected at explosives contaminated sites suggesting rapid dissemination of this novel catabolic activity, possibly within the 50-year period since the introduction of RDX into the environment. The X-ray structure of XplA-heme has been solved, providing fundamental information on the heme binding site. Interestingly, oxygen is not required for the degradation of RDX, but its presence determines the final degradation products, demonstrating that the degradation chemistry is flexible with both anaerobic and aerobic pathways resulting in the release of nitrite from the substrate. Transgenic plants expressing xplA are able to remove saturating levels of RDX from soil leachate and may provide a low cost sustainable remediation strategy for contaminated military sites. (C) 2010 Elsevier B.V. All rights reserved.

KW - RDX

KW - Explosive

KW - Cytochrome P450

KW - XplA

KW - XplB

KW - Bioremediation

KW - Phytoremediation

KW - SP STRAIN DN22

KW - HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE RDX

KW - RHODOCOCCUS SP

KW - CYCLOTRIMETHYLENETRINITRAMINE RDX

KW - MICROBIAL-DEGRADATION

KW - BIODEGRADATION

KW - BIOTRANSFORMATION

KW - MINERALIZATION

KW - METABOLITES

KW - CLONING

UR - http://www.scopus.com/inward/record.url?scp=78649447000&partnerID=8YFLogxK

U2 - 10.1016/j.bbapap.2010.07.004

DO - 10.1016/j.bbapap.2010.07.004

M3 - Article

SN - 1570-9639

VL - 1814

SP - 230

EP - 236

JO - BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS

JF - BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS

IS - 1

ER -