title: A point mutation of valine-311 to methionine in Bacillus subtilis protoporphyrinogen oxidase does not greatly increase resistance to the diphenyl ether herbicide oxyfluorfen.
abstract: In an effort to asses the effect of Val311Met point mutation of Bacillus subtilis protoporphyrinogen oxidase on the resistance to diphenyl ether herbicides, a Val311Met point mutant of B. subtilis protoporphyrinogen oxidase was prepared, heterologously expressed in Escherichia coli, and the purified recombinant Val311Met mutant protoporphyrinogen oxidase was kinetically characterized. The mutant protoporphyrinogen oxidase showed very similar kinetic patterns to wild type protoporphyrinogen oxidase, with slightly decreased activity dependent on pH and the concentrations of NaCl, Tween 20, and imidazole. When oxyfluorfen was used as a competitive inhibitor, the Val311Met mutant protoporphyrinogen oxidase showed an increased inhibition constant about 1.5 times that of wild type protoporphyrinogen oxidase. The marginal increase of the inhibition constant indicates that the Val311Met point mutation in B. subtilis protoporphyrinogen oxidase may not be an important determinant in the mechanism that protects protoporphyrinogen oxidase against diphenyl ether herbicides.
authors.affiliation: Department of Genetic Engineering, Biotechnology Research Institute, Agricultural Plant Stress Research Center, College of Agriculture and Life Science, Chonnam National University, 300 Yongbong-dong, Buk-gu, Kwangju, Republic of Korea.
authors.forename: Eunjoo
authors.initials: E
authors.lastname: Jeong
authors.forename: Thavrak
authors.initials: T
authors.lastname: Houn
authors.forename: Yongin
authors.initials: Y
authors.lastname: Kuk
authors.forename: Eun-Seon
authors.initials: ES
authors.lastname: Kim
authors.forename: Hema Kumar
authors.initials: HK
authors.lastname: Chandru
authors.forename: Myunggi
authors.initials: M
authors.lastname: Baik
authors.forename: Kyoungwhan
authors.initials: K
authors.lastname: Back
authors.forename: Ja-Ock
authors.initials: JO
authors.lastname: Guh
authors.forename: Oksoo
authors.initials: O
authors.lastname: Han
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D055768:Halogenated Diphenyl Ethers; D006540:Herbicides / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000494:pharmacology; D007700:Kinetics; D008715:Methionine / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008958:Models, Molecular; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010647:Phenyl Ethers / Q000494:pharmacology*; D017354:Point Mutation / Q000235:genetics*; D011136:Polysorbates / Q000494:pharmacology; D050768:Protoporphyrinogen Oxidase; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology; D014633:Valine / Q000235:genetics*
chemical_list: D055768:Halogenated Diphenyl Ethers; D006540:Herbicides; D007093:Imidazoles; D010647:Phenyl Ethers; D011136:Polysorbates; D012965:Sodium Chloride; C016027:oxyfluorofen; C029899:imidazole; D008715:Methionine; D044925:Oxidoreductases Acting on CH-CH Group Donors; D050768:Protoporphyrinogen Oxidase; D014633:Valine