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F420H2 oxidase (FprA) from Methanobrevibacter arboriphilus, a coenzyme F420-dependent enzyme involved in O2 detoxification.
Arch Microbiol. 2004 Oct; 182(2-3):126-37.AM

Abstract

Cell suspensions of Methanobrevibacter arboriphilus catalyzed the reduction of O(2) with H(2) at a maximal specific rate of 0.4 U (micromol/min) per mg protein with an apparent K(m) for O(2) of 30 microM. The reaction was not inhibited by cyanide. The oxidase activity was traced back to a coenzyme F(420)-dependent enzyme that was purified to apparent homogeneity and that catalyzed the oxidation of 2 F(420)H(2) with 1 O(2) to 2 F(420) and 2 H(2)O. The apparent K(m) for F(420) was 30 microM and that for O(2) was 2 microM with a V(max) of 240 U/mg at 37 degrees C and pH 7.6, the pH optimum of the oxidase. The enzyme did not use NADH or NADPH as electron donor or H(2)O(2) as electron acceptor and was not inhibited by cyanide. The 45-kDa protein, whose gene was cloned and sequenced, contained 1 FMN per mol and harbored a binuclear iron center as indicated by the sequence motif H-X-E-X-D-X(62)-H-X(18)-D-X(60)-H. Sequence comparisons revealed that the F(420)H(2) oxidase from M. arboriphilus is phylogenetically closely related to FprA from Methanothermobacter marburgensis (71% sequence identity), a 45-kDa flavoprotein of hitherto unknown function, and to A-type flavoproteins from bacteria (30-40%), which all have dioxygen reductase activity. With heterologously produced FprA from M. marburgensis it is shown that this protein is also a highly efficient F(420)H(2) oxidase and that it contains 1 FMN and 2 iron atoms. The presence of F(420)H(2) oxidase in methanogenic archaea may explain why some methanogens, e.g., the Methanobrevibacter species in the termite hindgut, cannot only tolerate but thrive under microoxic conditions.

Authors+Show Affiliations

Max-Planck-Institut für terrestrische Mikrobiologie und Laboratorium für Mikrobiologie des Fachbereichs Biologie, Philipps-Universität, Karl-von-Frisch-Strasse, 35043 Marburg, Germany.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15340796

Citation

Seedorf, Henning, et al. "F420H2 Oxidase (FprA) From Methanobrevibacter Arboriphilus, a Coenzyme F420-dependent Enzyme Involved in O2 Detoxification." Archives of Microbiology, vol. 182, no. 2-3, 2004, pp. 126-37.
Seedorf H, Dreisbach A, Hedderich R, et al. F420H2 oxidase (FprA) from Methanobrevibacter arboriphilus, a coenzyme F420-dependent enzyme involved in O2 detoxification. Arch Microbiol. 2004;182(2-3):126-37.
Seedorf, H., Dreisbach, A., Hedderich, R., Shima, S., & Thauer, R. K. (2004). F420H2 oxidase (FprA) from Methanobrevibacter arboriphilus, a coenzyme F420-dependent enzyme involved in O2 detoxification. Archives of Microbiology, 182(2-3), 126-37.
Seedorf H, et al. F420H2 Oxidase (FprA) From Methanobrevibacter Arboriphilus, a Coenzyme F420-dependent Enzyme Involved in O2 Detoxification. Arch Microbiol. 2004;182(2-3):126-37. PubMed PMID: 15340796.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - F420H2 oxidase (FprA) from Methanobrevibacter arboriphilus, a coenzyme F420-dependent enzyme involved in O2 detoxification. AU - Seedorf,Henning, AU - Dreisbach,Annette, AU - Hedderich,Reiner, AU - Shima,Seigo, AU - Thauer,Rudolf K, Y1 - 2004/08/31/ PY - 2004/02/11/received PY - 2004/04/04/revised PY - 2004/04/05/accepted PY - 2004/9/2/pubmed PY - 2005/4/19/medline PY - 2004/9/2/entrez SP - 126 EP - 37 JF - Archives of microbiology JO - Arch Microbiol VL - 182 IS - 2-3 N2 - Cell suspensions of Methanobrevibacter arboriphilus catalyzed the reduction of O(2) with H(2) at a maximal specific rate of 0.4 U (micromol/min) per mg protein with an apparent K(m) for O(2) of 30 microM. The reaction was not inhibited by cyanide. The oxidase activity was traced back to a coenzyme F(420)-dependent enzyme that was purified to apparent homogeneity and that catalyzed the oxidation of 2 F(420)H(2) with 1 O(2) to 2 F(420) and 2 H(2)O. The apparent K(m) for F(420) was 30 microM and that for O(2) was 2 microM with a V(max) of 240 U/mg at 37 degrees C and pH 7.6, the pH optimum of the oxidase. The enzyme did not use NADH or NADPH as electron donor or H(2)O(2) as electron acceptor and was not inhibited by cyanide. The 45-kDa protein, whose gene was cloned and sequenced, contained 1 FMN per mol and harbored a binuclear iron center as indicated by the sequence motif H-X-E-X-D-X(62)-H-X(18)-D-X(60)-H. Sequence comparisons revealed that the F(420)H(2) oxidase from M. arboriphilus is phylogenetically closely related to FprA from Methanothermobacter marburgensis (71% sequence identity), a 45-kDa flavoprotein of hitherto unknown function, and to A-type flavoproteins from bacteria (30-40%), which all have dioxygen reductase activity. With heterologously produced FprA from M. marburgensis it is shown that this protein is also a highly efficient F(420)H(2) oxidase and that it contains 1 FMN and 2 iron atoms. The presence of F(420)H(2) oxidase in methanogenic archaea may explain why some methanogens, e.g., the Methanobrevibacter species in the termite hindgut, cannot only tolerate but thrive under microoxic conditions. SN - 0302-8933 UR - https://www.unboundmedicine.com/medline/citation/15340796/F420H2_oxidase__FprA__from_Methanobrevibacter_arboriphilus_a_coenzyme_F420_dependent_enzyme_involved_in_O2_detoxification_ L2 - https://dx.doi.org/10.1007/s00203-004-0675-3 DB - PRIME DP - Unbound Medicine ER -