HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Identification of enzymes involved in anaerobic benzene degradation by a strictly anaerobic iron-reducing enrichment culture.

Abstract
Anaerobic benzene degradation was studied with a highly enriched iron-reducing culture (BF) composed of mainly Peptococcaceae-related Gram-positive microorganisms. The proteomes of benzene-, phenol- and benzoate-grown cells of culture BF were compared by SDS-PAGE. A specific benzene-expressed protein band of 60 kDa, which could not be observed during growth on phenol or benzoate, was subjected to N-terminal sequence analysis. The first 31 amino acids revealed that the protein was encoded by ORF 138 in the shotgun sequenced metagenome of culture BF. ORF 138 showed 43% sequence identity to phenylphosphate carboxylase subunit PpcA of Aromatoleum aromaticum strain EbN1. A LC/ESI-MS/MS-based shotgun proteomic analysis revealed other specifically benzene-expressed proteins with encoding genes located adjacent to ORF 138 on the metagenome. The protein products of ORF 137, ORF 139 and ORF 140 showed sequence identities of 37% to phenylphosphate carboxylase PpcD of A. aromaticum strain EbN1, 56% to benzoate-CoA ligase (BamY) of Geobacter metallireducens and 67% to 3-octaprenyl-4-hydroxybenzoate carboxy-lyase (UbiD/UbiX) of A. aromaticum strain EbN1 respectively. These genes are proposed as constituents of a putative benzene degradation gene cluster (∼ 17 kb) composed of carboxylase-related genes. The identified gene sequences suggest that the initial activation reaction in anaerobic benzene degradation is probably a direct carboxylation of benzene to benzoate catalysed by putative anaerobic benzene carboxylase (Abc). The putative Abc probably consists of several subunits, two of which are encoded by ORFs 137 and 138, and belongs to a family of carboxylases including phenylphosphate carboxylase (Ppc) and 3-octaprenyl-4-hydroxybenzoate carboxy-lyase (UbiD/UbiX).
AuthorsNidal Abu Laban, Draženka Selesi, Thomas Rattei, Patrick Tischler, Rainer U Meckenstock
JournalEnvironmental microbiology (Environ Microbiol) Vol. 12 Issue 10 Pg. 2783-96 (Oct 2010) ISSN: 1462-2920 [Electronic] England
PMID20545743 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
Copyright© 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.
Chemical References
  • Bacterial Proteins
  • Benzoates
  • Culture Media, Conditioned
  • Phenols
  • Iron
  • Carboxy-Lyases
  • Coenzyme A Ligases
  • benzoate coenzyme A ligase
  • Benzene
Topics
  • Anaerobiosis
  • Bacteria, Anaerobic (classification, enzymology, genetics)
  • Bacterial Proteins (genetics, metabolism)
  • Base Sequence
  • Benzene (metabolism)
  • Benzoates (metabolism)
  • Carboxy-Lyases (metabolism)
  • Coenzyme A Ligases (metabolism)
  • Culture Media, Conditioned
  • Genes, Bacterial
  • Gram-Positive Bacteria (classification, enzymology, genetics)
  • Hydroxylation
  • Iron (metabolism)
  • Methylation
  • Molecular Sequence Data
  • Multigene Family
  • Peptococcaceae (classification, enzymology)
  • Phenols (metabolism)
  • Sequence Analysis, Protein

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: