scholarly journals Cloning of the Arabidopsis and Rice Formaldehyde Dehydrogenase Genes: Implications for the Origin of Plant ADH Enzymes

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 1131-1141 ◽  
Author(s):  
R Dolferus ◽  
J C Osterman ◽  
W J Peacock ◽  
E S Dennis

This article reports the cloning of the genes encoding the Arabidopsis and rice class III ADH enzymes, members of the alcohol dehydrogenase or medium chain reductase/dehydrogenase superfamily of proteins with glutathione-dependent formaldehyde dehydrogenase activity (GSH-FDH). Both genes contain eight introns in exactly the same positions, and these positions are conserved in plant ethanolactive Adh genes (class P). These data provide further evidence that plant class P genes have evolved from class III genes by gene duplication and acquisition of new substrate specificities. The position of introns and similarities in the nucleic acid and amino acid sequences of the different classes of ADH enzymes in plants and humans suggest that plant and animal class I11 enzymes diverged before they duplicated to give rise to plant and animal ethanol-active ADH enzymes. Plant class P ADH enzymes have gained substrate specificities and evolved promoters with different expression properties, in keeping with their metabolic function as part of the alcohol fermentation pathway.

2006 ◽  
Vol 72 (5) ◽  
pp. 3321-3329 ◽  
Author(s):  
Kengo Inoue ◽  
Hiroshi Habe ◽  
Hisakazu Yamane ◽  
Hideaki Nojiri

ABSTRACT Nocardioides aromaticivorans IC177 is a gram-positive carbazole degrader. The genes encoding carbazole degradation (car genes) were cloned into a cosmid clone and sequenced partially to reveal 19 open reading frames. The car genes were clustered into the carAaCBaBbAcAd and carDFE gene clusters, encoding the enzymes responsible for the degradation of carbazole to anthranilate and 2-hydroxypenta-2,4-dienoate and of 2-hydroxypenta-2,4-dienoate to pyruvic acid and acetyl coenzyme A, respectively. The conserved amino acid motifs proposed to bind the Rieske-type [2Fe-2S] cluster and mononuclear iron, the Rieske-type [2Fe-2S] cluster, and flavin adenine dinucleotide were found in the deduced amino acid sequences of carAa, carAc, and carAd, respectively, which showed similarities with CarAa from Sphingomonas sp. strain KA1 (49% identity), CarAc from Pseudomonas resinovorans CA10 (31% identity), and AhdA4 from Sphingomonas sp. strain P2 (37% identity), respectively. Escherichia coli cells expressing CarAaAcAd exhibited major carbazole 1,9a-dioxygenase (CARDO) activity. These data showed that the IC177 CARDO is classified into class IIB, while gram-negative CARDOs are classified into class III or IIA, indicating that the respective CARDOs have diverse types of electron transfer components and high similarities of the terminal oxygenase. Reverse transcription-PCR (RT-PCR) experiments showed that the carAaCBaBbAcAd and carDFE gene clusters are operonic. The results of quantitative RT-PCR experiments indicated that transcription of both operons is induced by carbazole or its metabolite, whereas anthranilate is not an inducer. Biotransformation analysis showed that the IC177 CARDO exhibits significant activities for naphthalene, carbazole, and dibenzo-p-dioxin but less activity for dibenzofuran and biphenyl.


2009 ◽  
Vol 192 (2) ◽  
pp. 446-455 ◽  
Author(s):  
Christiane Albert-Weissenberger ◽  
Tobias Sahr ◽  
Odile Sismeiro ◽  
Jörg Hacker ◽  
Klaus Heuner ◽  
...  

ABSTRACT The bacterial pathogen Legionella pneumophila responds to environmental changes by differentiation. At least two forms are well described: replicative bacteria are avirulent; in contrast, transmissive bacteria express virulence traits and flagella. Phenotypic analysis, Western blotting, and electron microscopy of mutants of the regulatory genes encoding RpoN, FleQ, FleR, and FliA demonstrated that flagellin expression is strongly repressed and that the mutants are nonflagellated in the transmissive phase. Transcriptome analyses elucidated that RpoN, together with FleQ, enhances transcription of 14 out of 31 flagellar class II genes, which code for the basal body, hook, and regulatory proteins. Unexpectedly, FleQ independent of RpoN enhances the transcription of fliA encoding sigma 28. Expression analysis of a fliA mutant showed that FliA activates three out of the five remaining flagellar class III genes and the flagellar class IV genes. Surprisingly, FleR does not induce but inhibits expression of at least 14 flagellar class III genes on the transcriptional level. Thus, we propose that flagellar class II genes are controlled by FleQ and RpoN, whereas the transcription of the class III gene fliA is controlled in a FleQ-dependent but RpoN-independent manner. However, RpoN and FleR might influence flagellin synthesis on a posttranscriptional level. In contrast to the commonly accepted view that enhancer-binding proteins such as FleQ always interact with RpoN to fullfill their regulatory functions, our results strongly indicate that FleQ regulates gene expression that is RpoN dependent and RpoN independent. Finally, FliA induces expression of flagellar class III and IV genes leading to the complete synthesis of the flagellum.


Genetics ◽  
1993 ◽  
Vol 133 (4) ◽  
pp. 999-1007
Author(s):  
R G Gregerson ◽  
L Cameron ◽  
M McLean ◽  
P Dennis ◽  
J Strommer

Abstract In most higher plants the genes encoding alcohol dehydrogenase comprise a small gene family, usually with two members. The Adh1 gene of Petunia has been cloned and analyzed, but a second identifiable gene was not recovered from any of three genomic libraries. We have therefore employed the polymerase chain reaction to obtain the major portion of a second Adh gene. From sequence, mapping and northern data we conclude this gene encodes ADH2, the major anaerobically inducible Adh gene of Petunia. The availability of both Adh1 and Adh2 from Petunia has permitted us to compare their structures and patterns of expression to those of the well-studied Adh genes of maize, of which one is highly expressed developmentally, while both are induced in response to hypoxia. Despite their evolutionary distance, evidenced by deduced amino acid sequence as well as taxonomic classification, the pairs of genes are regulated in strikingly similar ways in maize and Petunia. Our findings suggest a significant biological basis for the regulatory strategy employed by these distant species for differential expression of multiple Adh genes.


2005 ◽  
Vol 51 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Hidenori Hayashi ◽  
Takashi Abe ◽  
Mitsuo Sakamoto ◽  
Hiroki Ohara ◽  
Toshimichi Ikemura ◽  
...  

The aim of this study was to identify a novel 1,4-β-xylanase gene from the mixed genome DNA of human fecal bacteria without bacterial cultivation. Total DNA was isolated from a population of bacteria extracted from fecal microbiota. Using PCR, the gene fragments encoding 5 different family 10 xylanases (xyn10A, xyn10B, xyn10C, xyn10D, and xyn10E) were found. Amino acid sequences deduced from these genes were highly homologous with those of xylanases from anaerobic intestinal bacteria such as Bacteroides spp. and Prevotella spp. Self-organizing map (SOM) analysis revealed that xynA10 was classified into Bacteroidetes. To confirm that one of these genes encodes an active enzyme, a full-length xyn10A gene was obtained using nested primers specific to the internal fragments and random primers. The xyn10A gene encoding the xylanase Xyn10A consists of 1146 bp and encodes a protein of 382 amino acids and a molecular weight of 43 552. Xyn10A was a single module novel xylanase. Xyn10A was purified from a recombinant Escherichia coli strain and characterized. This enzyme was optimally active at 40 °C and stable up to 50 °C at pH 6.5 and over the pH range 4.0–11.0 at 25 °C. In addition, 2 ORFs (ORF1 and ORF2) were identified upstream of xyn10A. These results suggested that many unidentified xylanolytic bacteria exist in the human gut and may contribute to the breakdown of xylan which contains dietary fiber.Key words: xylanase, human gut, fecal microbiota, phylogenetic analysis, self-organizing map.


1991 ◽  
Vol 11 (2) ◽  
pp. 963-971
Author(s):  
B Fenton ◽  
J T Clark ◽  
C M Khan ◽  
J V Robinson ◽  
D Walliker ◽  
...  

Merozoite surface antigen MSA-2 of the human parasite Plasmodium falciparum is being considered for the development of a malaria vaccine. The antigen is polymorphic, and specific monoclonal antibodies differentiate five serological variants of MSA-2 among 25 parasite isolates. The variants are grouped into two major serogroups, A and B. Genes encoding two different variants from serogroup A have been sequenced, and their DNA together with deduced amino acid sequences were compared with sequences encoded by other alleles. The comparison shows that the serological classification reflects differences in DNA sequences and deduced primary structure of MSA-2 variants and serogroups. Thus, the overall homologies of DNA and amino acid sequences are over 95% among variants in the same serogroup. In contrast, similarities between the group A variants and a group B variant are only 70 and 64% for DNA and amino acid sequences, respectively. We propose that the MSA-2 protein is encoded by two highly divergent groups of alleles, with limited additional polymorphism displayed within each group.


1969 ◽  
Vol 4 (2) ◽  
pp. 353-367
Author(s):  
H. SUBAK-SHARPE ◽  
R. R. BÜRK ◽  
J. D. PITTS

Cells of a genetic variant of the hamster fibroblast line BHK 21 which lack inosinic pyrophosphorylase activity (IPP- cells) and therefore cannot normally incorporate [3H]hypoxanthine were grown in mixed culture with cells of BHK 21 sublines which have inosinic pyrophosphorylase activity (IPP+ cells). If not in contact with IPP+ cells, IPP- cells do not incorporate added [3H]hypoxanthine into nucleic acid. IPP+ cells always do incorporate [3H]hypoxanthine and IPP- cells when in direct or indirect contact with IPP+ cells also incorporate the isotope. Cell to cell contact appears to be essential for this gain of a metabolic function by IPP- cells. The possible molecular basis and general implications of the phenomenon are discussed.


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