Previous Article | Next Article ![]()
Journal of Bacteriology, February 2000, p. 789-795, Vol. 182, No. 3
Departamento de Genética, Facultad de
Biología, Universidad de Sevilla, 41080 Seville,
Spain,1 and Chemische Mikrobiologie,
Bergische Universität-Gesamthochschule Wuppertal, D-42097
Wuppertal, Germany2
Received 8 September 1999/Accepted 9 November 1999
A genomic region involved in tetralin biodegradation was recently
identified in Sphingomonas strain TFA. We have cloned and sequenced from this region a gene designated thnC, which
codes for an extradiol dioxygenase required for tetralin utilization. Comparison to similar sequences allowed us to define a subfamily of
1,2-dihydroxynaphthalene extradiol dioxygenases, which comprises two
clearly different groups, and to show that ThnC clusters within group 2 of this subfamily. 1,2-Dihydroxy-5,6,7,8-tetrahydronaphthalene was
found to be the metabolite accumulated by a thnC insertion mutant. The ring cleavage product of this metabolite exhibited behavior
typical of a hydroxymuconic semialdehyde toward pH-dependent changes
and derivatization with ammonium to give a quinoline derivative. The
gene product has been purified, and its biochemical properties have
been studied. The enzyme is a decamer which requires Fe(II) for
activity and shows high activity toward its substrate
(Vmax, 40.5 U mg
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Identification of an Extradiol Dioxygenase Involved
in Tetralin Biodegradation: Gene Sequence Analysis and Purification and
Characterization of the Gene Product
1;
Km, 18.6 µM). The enzyme shows even higher
activity with 1,2-dihydroxynaphthalene and also significant activity
toward 1,2-dihydroxybiphenyl or methylated catechols. The broad
substrate specificity of ThnC is consistent with that exhibited by
other extradiol dioxygenases of the same group within the subfamily of
1,2-dihydroxynaphthalene dioxygenases.
*
Corresponding author. Mailing address: Departamento de
Genética, Facultad de Biología, Universidad de Sevilla,
Ap. 1095, 41080 Sevilla, Spain. Phone: 34-95-4557106. Fax:
34-95-4557104. E-mail: esantero{at}cica.es.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»