A 2,598-base-pair (bp) SalI-HincII DNA fragment has been cloned which codes for vanillate demethylase, the enzyme responsible for the demethylation of vanillate (3-methoxy-4-hydroxybenzoate) to protocatechuate (3,4-dihydroxybenzoate). Complementation and insertional inactivation experiments have shown that this fragment carries two genes (vanA and vanB) which are predominantly cotranscribed from a promoter upstream of vanA. Nucleotide sequencing of the SalI-HincII fragment confirmed the genetic data: two open reading frames of 987 and 942 bp were present in the transcribed orientation. These had a very high G + C content in the third base of each codon, which is characteristic of Pseudomonas chromosomal genes. Expression of the genes in Escherichia coli with the T7 RNA polymerase-promoter system gave rise to two polypeptides of 36 and 33 kilodaltons which could be identified by deletion analysis as the products of vanA and vanB, respectively. A search of the protein sequence data bank indicated that the vanB gene product was related to the ferredoxin family.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC211539 | PMC |
| http://dx.doi.org/10.1128/jb.170.10.4924-4930.1988 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Engineering a vanillate-producing strain of Pseudomonas sp. NGC7 corresponding to aromatic compounds derived from the continuous catalytic alkaline oxidation of sulfite lignin.
Microb Cell Fact
November 2024
Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Aomori, 036-8561, Japan.
Introduction: Lignin is a promising resource for obtaining aromatic materials, however, its heterogeneous structure poses a challenge for effective utilization. One approach to produce homogeneous aromatic materials from lignin involves the application of microbial catabolism, which is gaining attention. This current study focused on constructing a catabolic pathway in Pseudomonas sp.
View Article and Find Full Text PDFEvolution and engineering of pathways for aromatic O-demethylation in Pseudomonas putida KT2440.
Metab Eng
July 2024
Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA. Electronic address:
Biological conversion of lignin from biomass offers a promising strategy for sustainable production of fuels and chemicals. However, aromatic compounds derived from lignin commonly contain methoxy groups, and O-demethylation of these substrates is often a rate-limiting reaction that influences catabolic efficiency. Several enzyme families catalyze aromatic O-demethylation, but they are rarely compared in vivo to determine an optimal biocatalytic strategy.
View Article and Find Full Text PDFBiological Valorization of Lignin-Derived Aromatics in Hydrolysate to Protocatechuic Acid by Engineered KT2440.
Molecules
March 2024
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
Alongside fermentable sugars, weak acids, and furan derivatives, lignocellulosic hydrolysates contain non-negligible amounts of lignin-derived aromatic compounds. The biological funnel of lignin offers a new strategy for the "natural" production of protocatechuic acid (PCA). Herein, KT2440 was engineered to produce PCA from lignin-derived monomers in hydrolysates by knocking out protocatechuate 3,4-dioxygenase and overexpressing vanillate--demethylase endogenously, while acetic acid was used for cell growth.
View Article and Find Full Text PDFThe catabolism of lignin-derived -methoxylated aromatic compounds by RHA1.
Appl Environ Microbiol
March 2024
Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, Canada.
Emergent strategies to valorize lignin, an abundant but underutilized aromatic biopolymer, include tandem processes that integrate chemical depolymerization and biological catalysis. To date, aromatic monomers from C-O bond cleavage of lignin have been converted to bioproducts, but the presence of recalcitrant C-C bonds in lignin limits the product yield. A promising chemocatalytic strategy that overcomes this limitation involves phenol methyl protection and autoxidation.
View Article and Find Full Text PDFIdentification of a Phylogenetically Divergent Vanillate O-Demethylase from R1 Supporting Growth on -Methoxylated Aromatic Acids.
Microorganisms
December 2022
Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación (PIDi), Universidad Tecnológica Metropolitana, Santiago 8940577, Chile.
Rieske-type two-component vanillate O-demethylases (VanODs) catalyze conversion of the lignin-derived monomer vanillate into protocatechuate in several bacterial species. Currently, VanODs have received attention because of the demand of effective lignin valorization technologies, since these enzymes own the potential to catalyze methoxy group demethylation of distinct lignin monomers. In this work, we identified a phylogenetically divergent VanOD from R1, only distantly related to previously described homologues and whose presence, along with a 3-hydroxybenzoate/gentisate pathway, correlated with the ability to grow on other meta-methoxylated aromatics, such as 3-methoxybenzoate and 5-methoxysalicylate.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!