Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Dec 1995, 4284-4290, Vol 61, No. 12
AV Yabannavar and GJ Zylstra
Pseudomonas pickettii YH105 was isolated for its ability to utilize p-
nitrobenzoate as the sole source of carbon, nitrogen, and energy.
Degradation of p-nitrobenzoate by this strain proceeds through a reductive
route as evidenced by the accumulation of ammonia in the culture medium
during growth on p-nitrobenzoate. Enzyme assays and high- performance
liquid chromatography (HPLC) analysis of culture supernatants indicate that
p-nitrobenzoate is degraded through p- hydroxylaminobenzoate and
protocatechuate. In order to clone the genes responsible for the initial
steps in the catabolic pathway, a cosmid library was constructed with P.
pickettii YH105 genomic DNA. The library was screened for clones capable of
transforming p-nitrobenzoate to protocatechuate, using a plate assay
specific for diphenolic compounds. HPLC analysis of culture supernatants
confirmed that the cosmid clones did indeed produce protocatechuate from
p-nitrobenzoate. Five positive cosmid clones that possessed this activity
were identified. Restriction digests of the cosmid clones indicated that
all of the clones had two EcoRI fragments in common (3.9 and 1.0 kb). One
of these cosmid clones, designated pGJZ1601, was chosen for further
analysis. Subcloning and activity assay experiments localized the genes
responsible for the conversion of p-nitrobenzoate to protocatechuate to a
1.4-kb SalI-SphI DNA fragment. Further subcloning experiments localized the
gene coding for p-nitrobenzoate reductase, responsible for the first
enzymatic step in the catabolic pathway, to a 0.8-kb SalI- ApaI DNA
fragment. The gene for the second step in the catabolic pathway, coding for
hydroxylaminolyase, was located adjacent to the gene for the
p-nitrobenzoate reductase.
Copyright © 1995, American Society for Microbiology
Cloning and characterization of the genes for p-nitrobenzoate degradation from Pseudomonas pickettii YH105
Center for Agricultural Molecular Biology, Cook College, Rutgers University, New Brunswick, New Jersey 08903-0231, USA.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|