PMID- 8981999
OWN - NLM
STAT- MEDLINE
DCOM- 19970206
LR  - 20190508
IS  - 0021-9193 (Print)
IS  - 1098-5530 (Electronic)
IS  - 0021-9193 (Linking)
VI  - 179
IP  - 1
DP  - 1997 Jan
TI  - Purification and characterization of 2,4,6-trichlorophenol-4-monooxygenase, a 
      dehalogenating enzyme from Azotobacter sp. strain GP1.
PG  - 202-8
AB  - The enzyme which catalyzes the dehalogenation of 2,4,6-trichlorophenol (TCP) was 
      purified to apparent homogeneity from an extract of TCP-induced cells of 
      Azotobacter sp. strain GP1. The initial step of TCP degradation in this bacterium 
      is inducible by TCP; no activity was found in succinate-grown cells or in 
      phenol-induced cells. NADH, flavin adenine dinucleotide, and O2 are required as 
      cofactors. As reaction products, 2,6-dichlorohydroquinone and Cl- ions were 
      identified. Studies of the stoichiometry revealed the consumption of 2 mol of 
      NADH plus 1 mol of O2 per mol of TCP and the formation of 1 mol of Cl- ions. No 
      evidence for membrane association or for a multicomponent system was obtained. 
      Molecular masses of 240 kDa for the native enzyme and 60 kDa for the subunit were 
      determined, indicating a homotetrameric structure. Cross-linking studies with 
      dimethylsuberimidate were consistent with this finding. TCP was the best 
      substrate for 2,4,6-trichlorophenol-4-monooxygenase (TCP-4-monooxygenase). The 
      majority of other chlorophenols converted by the enzyme bear a chloro substituent 
      in the 4-position. 2,6-Dichlorophenol, also accepted as a substrate, was 
      hydroxylated in the 4-position to 2,6-dichlorohydroquinone in a nondehalogenating 
      reaction. NADH and O2 were consumed by the pure enzyme also in the absence of TCP 
      with simultaneous production of H2O2. The NH2-terminal amino acid sequence of 
      TCP-4-monooxygenase from Azotobacter sp. strain GP1 revealed complete identity 
      with the nucleotide-derived sequence from the analogous enzyme from Pseudomonas 
      pickettii and a high degree of homology with two nondehalogenating 
      monooxygenases. The similarity in enzyme properties and the possible evolutionary 
      relatedness of dehalogenating and nondehalogenating monooxygenases are discussed.
FAU - Wieser, M
AU  - Wieser M
AD  - Institut fur Mikrobiologie, Universitat Hohenheim, Stuttgart, Germany.
FAU - Wagner, B
AU  - Wagner B
FAU - Eberspacher, J
AU  - Eberspacher J
FAU - Lingens, F
AU  - Lingens F
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Bacteriol
JT  - Journal of bacteriology
JID - 2985120R
RN  - 0 (Chlorides)
RN  - 0 (Chlorophenols)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Metals)
RN  - 0U46U6E8UK (NAD)
RN  - 146-14-5 (Flavin-Adenine Dinucleotide)
RN  - EC 1.- (Mixed Function Oxygenases)
RN  - MHS8C5BAUZ (2,4,6-trichlorophenol)
SB  - IM
MH  - Amino Acid Sequence
MH  - Azotobacter/*enzymology
MH  - Biodegradation, Environmental
MH  - Chlorides/metabolism
MH  - Chlorophenols/*metabolism
MH  - Cytoplasm/enzymology
MH  - Enzyme Induction
MH  - Enzyme Inhibitors/pharmacology
MH  - Flavin-Adenine Dinucleotide/metabolism
MH  - Hydrogen-Ion Concentration
MH  - Metals/pharmacology
MH  - Mixed Function Oxygenases/antagonists & inhibitors/chemistry/*isolation & 
      purification/*metabolism
MH  - Models, Chemical
MH  - Molecular Sequence Data
MH  - Molecular Weight
MH  - NAD/metabolism
MH  - Oxygen Consumption
MH  - Substrate Specificity
MH  - Temperature
PMC - PMC178680
EDAT- 1997/01/01 00:00
MHDA- 1997/01/01 00:01
PMCR- 1997/01/01
CRDT- 1997/01/01 00:00
PHST- 1997/01/01 00:00 [pubmed]
PHST- 1997/01/01 00:01 [medline]
PHST- 1997/01/01 00:00 [entrez]
PHST- 1997/01/01 00:00 [pmc-release]
AID - 10.1128/jb.179.1.202-208.1997 [doi]
PST - ppublish
SO  - J Bacteriol. 1997 Jan;179(1):202-8. doi: 10.1128/jb.179.1.202-208.1997.