scholarly journals Cloning, sequence analysis and over-expression of the gene for the class II fructose 1,6-bisphosphate aldolase of Escherichia coli

1989 ◽  
Vol 257 (2) ◽  
pp. 529-534 ◽  
Author(s):  
P R Alefounder ◽  
S A Baldwin ◽  
R N Perham ◽  
N J Short

Nucleotide sequence analysis of the Escherichia coli chromosomal DNA inserted in the plasmid pLC33-5 of the Clarke and Carbon library [Clarke & Carbon (1976) Cell 9, 91-99] revealed the existence of the gene, fda, encoding the Class II (metal-dependent) fructose 1,6-bisphosphate aldolase of E. coli. The primary structure of the polypeptide chain inferred from the DNA sequence of the fda gene comprises 359 amino acids, including the initiating methionine residue, from which an Mr of 39,146 could be calculated. This value is in good agreement with that of 40,000 estimated from sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the purified dimeric enzyme. The amino acid sequence of the Class II aldolase from E. coli showed no homology with the known amino acid sequences of Class I (imine-forming) fructose 1,6-bisphosphate aldolases from a wide variety of sources. On the other hand, there was obvious homology with the N-terminal sequence of 40 residues already established for the Class II fructose 1,6-bisphosphate aldolase of Saccharomyces cerevisiae. These Class II aldolases, one from a prokaryote and one from a eukaryote, evidently are structurally and evolutionarily related. A 1029 bp-fragment of DNA incorporating the fda gene was excised from plasmid pLC33-5 by digestion with restriction endonuclease HaeIII and subcloned into the expression plasmid pKK223-3, where the gene came under the control of the tac promoter. When grown in the presence of the inducer isopropyl-beta-D-thiogalactopyranoside, E. coli JM101 cells transformed with this recombinant expression plasmid generated the Class II fructose 1,6-bisphosphate aldolase as approx. 70% of their soluble protein. This unusually high expression of an E. coli gene should greatly facilitate purification of the enzyme for any future structural or mechanistic studies.

1978 ◽  
Vol 169 (3) ◽  
pp. 633-641 ◽  
Author(s):  
S A Baldwin ◽  
R N Perham ◽  
D Stribling

A new form of the class-II D-fructose 1,6-bisphosphate aldolase (EC 4.1.2.13) of Escherichia coli (Crookes' strain) was isolated from an extract of glycerol-grown bacteria. It has a higher molecular weight (approx. 80000)than previous preparations of the enzyme and closely resembles the typical class-II aldolase from yeast in size and amino acid composition. On the other hand, its kinetic behaviour is not typical of a class-II aldolase. The enzyme has no requirement for thiol compounds either for stability or activity, added K+ ions have no effect, and the optimum pH for the cleavage activity is unusually high. The class-II enzymes from the prokaryote E. coli and the eukaryote yeast show no immunological identity. However, the similarity of their structures suggests that they have evolved from a common ancestor.


2002 ◽  
Vol 184 (11) ◽  
pp. 2906-2913 ◽  
Author(s):  
Keietsu Abe ◽  
Fumito Ohnishi ◽  
Kyoko Yagi ◽  
Tasuku Nakajima ◽  
Takeshi Higuchi ◽  
...  

ABSTRACT Tetragenococcus halophila D10 catalyzes the decarboxylation of l-aspartate with nearly stoichiometric release of l-alanine and CO2. This trait is encoded on a 25-kb plasmid, pD1. We found in this plasmid a putative asp operon consisting of two genes, which we designated aspD and aspT, encoding an l-aspartate-β-decarboxylase (AspD) and an aspartate-alanine antiporter (AspT), respectively, and determined the nucleotide sequences. The sequence analysis revealed that the genes of the asp operon in pD1 were in the following order: promoter → aspD → aspT. The deduced amino acid sequence of AspD showed similarity to the sequences of two known l-aspartate-β-decarboxylases from Pseudomonas dacunhae and Alcaligenes faecalis. Hydropathy analyses suggested that the aspT gene product encodes a hydrophobic protein with multiple membrane-spanning regions. The operon was subcloned into the Escherichia coli expression vector pTrc99A, and the two genes were cotranscribed in the resulting plasmid, pTrcAsp. Expression of the asp operon in E. coli coincided with appearance of the capacity to catalyze the decarboxylation of aspartate to alanine. Histidine-tagged AspD (AspDHis) was also expressed in E. coli and purified from cell extracts. The purified AspDHis clearly exhibited activity of l-aspartate-β-decarboxylase. Recombinant AspT was solubilized from E. coli membranes and reconstituted in proteoliposomes. The reconstituted AspT catalyzed self-exchange of aspartate and electrogenic heterologous exchange of aspartate with alanine. Thus, the asp operon confers a proton motive metabolic cycle consisting of the electrogenic aspartate-alanine antiporter and the aspartate decarboxylase, which keeps intracellular levels of alanine, the countersubstrate for aspartate, high.


2004 ◽  
Vol 70 (3) ◽  
pp. 1570-1575 ◽  
Author(s):  
Dae Heoun Baek ◽  
Jae Jun Song ◽  
Seok-Joon Kwon ◽  
Chung Park ◽  
Chang-Min Jung ◽  
...  

ABSTRACT A new thermostable dipeptidase gene was cloned from the thermophile Brevibacillus borstelensis BCS-1 by genetic complementation of the d-Glu auxotroph Escherichia coli WM335 on a plate containing d-Ala-d-Glu. Nucleotide sequence analysis revealed that the gene included an open reading frame coding for a 307-amino-acid sequence with an M r of 35,000. The deduced amino acid sequence of the dipeptidase exhibited 52% similarity with the dipeptidase from Listeria monocytogenes. The enzyme was purified to homogeneity from recombinant E. coli WM335 harboring the dipeptidase gene from B. borstelensis BCS-1. Investigation of the enantioselectivity (E) to the P1 and P1′ site of Ala-Ala revealed that the ratio of the specificity constant (k cat /Km ) for l-enantioselectivity to the P1 site of Ala-Ala was 23.4 � 2.2 [E = (k cat /Km ) l,d /(k cat /Km ) d,d ], while the d-enantioselectivity to the P1′ site of Ala-Ala was 16.4 � 0.5 [E = (k cat /Km ) l,d /(k cat /Km ) l,l ] at 55�C. The enzyme was stable up to 55�C, and the optimal pH and temperature were 8.5 and 65�C, respectively. The enzyme was able to hydrolyze l-Asp-d-Ala, l-Asp-d-AlaOMe, Z-d-Ala-d-AlaOBzl, and Z-l-Asp-d-AlaOBzl, yet it could not hydrolyze d-Ala-l-Asp, d-Ala-l-Ala, d-AlaNH2, and l-AlaNH2. The enzyme also exhibited β-lactamase activity similar to that of a human renal dipeptidase. The dipeptidase successfully synthesized the precursor of the dipeptide sweetener Z-l-Asp-d-AlaOBzl.


2003 ◽  
Vol 69 (7) ◽  
pp. 3791-3797 ◽  
Author(s):  
Nobuyuki Horinouchi ◽  
Jun Ogawa ◽  
Takafumi Sakai ◽  
Takako Kawano ◽  
Seiichiro Matsumoto ◽  
...  

ABSTRACT The gene encoding a deoxyriboaldolase (DERA) was cloned from the chromosomal DNA of Klebsiella pneumoniae B-4-4. This gene contains an open reading frame consisting of 780 nucleotides encoding 259 amino acid residues. The predicted amino acid sequence exhibited 94.6% homology with the sequence of DERA from Escherichia coli. The DERA of K. pneumoniae was expressed in recombinant E. coli cells, and the specific activity of the enzyme in the cell extract was as high as 2.5 U/mg, which was threefold higher than the specific activity in the K. pneumoniae cell extract. One of the E. coli transformants, 10B5/pTS8, which had a defect in alkaline phosphatase activity, was a good catalyst for 2-deoxyribose 5-phosphate (DR5P) synthesis from glyceraldehyde 3-phosphate and acetaldehyde. The E. coli cells produced DR5P from glucose and acetaldehyde in the presence of ATP. Under the optimal conditions, 100 mM DR5P was produced from 900 mM glucose, 200 mM acetaldehyde, and 100 mM ATP by the E. coli cells. The DR5P produced was further transformed to 2′-deoxyribonucleoside through coupling the enzymatic reactions of phosphopentomutase and nucleoside phosphorylase. These results indicated that production of 2′-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase is possible with the addition of a suitable energy source, such as ATP.


2000 ◽  
Vol 182 (2) ◽  
pp. 469-476 ◽  
Author(s):  
Frank J. Ruzicka ◽  
Kafryn W. Lieder ◽  
Perry A. Frey

ABSTRACT Lysine 2,3-aminomutase (KAM, EC 5.4.3.2 .) catalyzes the interconversion of l-lysine and l-β-lysine, the first step in lysine degradation in Clostridium subterminale SB4. KAM requires S-adenosylmethionine (SAM), which mediates hydrogen transfer in a mechanism analogous to adenosylcobalamin-dependent reactions. KAM also contains an iron-sulfur cluster and requires pyridoxal 5′-phosphate (PLP) for activity. In the present work, we report the cloning and nucleotide sequencing of the gene kamA for C. subterminale SB4 KAM and conditions for its expression in Escherichia coli. The cyanogen bromide peptides were isolated and characterized by mass spectral analysis and, for selected peptides, amino acid and N-terminal amino acid sequence analysis. PCR was performed with degenerate oligonucleotide primers and C. subterminale SB4 chromosomal DNA to produce a portion of kamA containing 1,029 base pairs of the gene. The complete gene was obtained from a genomic library of C. subterminale SB4 chromosomal DNA by use of DNA probe analysis based on the 1,029-base pair fragment. The full-length gene consisted of 1,251 base pairs specifying a protein of 47,030 Da, in reasonable agreement with 47,173 Da obtained by electrospray mass spectrometry of the purified enzyme. N- and C-terminal amino acid analysis of KAM and its cyanogen bromide peptides firmly correlated its amino acid sequence with the nucleotide sequence of kamA. A survey of bacterial genome databases identified seven homologs with 31 to 72% sequence identity to KAM, none of which were known enzymes. An E. coli expression system consisting of pET 23a(+) plus kamA yielded unsatisfactory expression and bacterial growth. Codon usage in kamA includes the use of AGA for all 29 arginine residues. AGA is rarely used in E. coli, and arginine clusters at positions 4 and 5, 25 and 27, and 134, 135, and 136 apparently compound the barrier to expression. Coexpression of E. coli argU dramatically enhanced both cell growth and expression of KAM. Purified recombinant KAM is equivalent to that purified from C. subterminale SB4.


2002 ◽  
Vol 184 (23) ◽  
pp. 6544-6550 ◽  
Author(s):  
Florence K. Gleason ◽  
Neil E. Olszewski

ABSTRACT The gene for ribonucleotide reductase from Anabaena sp. strain PCC 7120 was identified and expressed in Escherichia coli. This gene codes for a 1,172-amino-acid protein that contains a 407-amino-acid intein. The intein splices itself from the protein when it is expressed in E. coli, yielding an active ribonucleotide reductase of 765 residues. The mature enzyme was purified to homogeneity from E. coli extracts. Anabaena ribonucleotide reductase is a monomer with a molecular weight of approximately 88,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Superose 12 column chromatography. The enzyme reduces ribonucleotides at the triphosphate level and requires a divalent cation and a deoxyribonucleoside triphosphate effector. The enzyme is absolutely dependent on the addition of the cofactor, 5′-adenosylcobalamin. These properties are characteristic of the class II-type reductases. The cyanobacterial enzyme has limited sequence homology to other class II reductases; the greatest similarity (38%) is to the reductase from Lactobacillus leichmannii. In contrast, the Anabaena reductase shows over 90% sequence similarity to putative reductases found in genome sequences of other cyanobacteria, such as Nostoc punctiforme, Synechococcus sp. strain WH8102, and Prochlorococcus marinus MED4, suggesting that the cyanobacterial reductases form a closely related subset of the class II enzymes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Femi Ayoade ◽  
Judith Oguzie ◽  
Philomena Eromon ◽  
Omolola E. Omotosho ◽  
Tosin Ogunbiyi ◽  
...  

AbstractShiga toxigenic strains of E. coli (STEC) known to be etiological agents for diarrhea were screened for their incidence/occurrence in selected abattoirs sources in Osogbo metropolis of Osun State, Nigeria using a randomized block design. Samples were plated directly on selective and differential media and E. coli isolates. Multiplex PCR analysis was used to screen for the presence of specific virulence factors. These were confirmed serologically as non-O157 STEC using latex agglutination serotyping kit. Sequence analysis of PCR products was performed on a representative isolate showing the highest combination of virulence genes using the 16S gene for identification purposes only. Results showed that the average cfu/cm2 was significantly lower in the samples collected at Sekona-2 slaughter slab compared with those collected at Al-maleek batch abattoir and Sekona-1 slaughter slab in ascending order at P = 0.03. Moreover, the average cfu/cm2E. coli in samples collected from butchering knife was significantly lower when compared with that of the workers’ hand (P = 0.047) and slaughtering floor (P = 0.047) but not with the slaughter table (P = 0.98) and effluent water from the abattoir house (P = 0.39). These data suggest that the abattoir type may not be as important in the prevalence and spread of STEC as the hygiene practices of the workers. Sequence analysis of a representative isolate showed 100% coverage and 96.46% percentage identity with Escherichia coli O113:H21 (GenBank Accession number: CP031892.1) strain from Canada. This sequence was subsequently submitted to GenBank with accession number MW463885. From evolutionary analyses, the strain from Nigeria, sequenced in this study, is evolutionarily distant when compared with the publicly available sequences from Nigeria. Although no case of E. coli O157 was found within the study area, percent occurrence of non-O157 STEC as high as 46.3% at some of the sampled sites is worrisome and requires regulatory interventions in ensuring hygienic practices at the abattoirs within the study area.


2021 ◽  
Vol 22 (3) ◽  
pp. 1018
Author(s):  
Hiroaki Yokota

Helicases are nucleic acid-unwinding enzymes that are involved in the maintenance of genome integrity. Several parts of the amino acid sequences of helicases are very similar, and these quite well-conserved amino acid sequences are termed “helicase motifs”. Previous studies by X-ray crystallography and single-molecule measurements have suggested a common underlying mechanism for their function. These studies indicate the role of the helicase motifs in unwinding nucleic acids. In contrast, the sequence and length of the C-terminal amino acids of helicases are highly variable. In this paper, I review past and recent studies that proposed helicase mechanisms and studies that investigated the roles of the C-terminal amino acids on helicase and dimerization activities, primarily on the non-hexermeric Escherichia coli (E. coli) UvrD helicase. Then, I center on my recent study of single-molecule direct visualization of a UvrD mutant lacking the C-terminal 40 amino acids (UvrDΔ40C) used in studies proposing the monomer helicase model. The study demonstrated that multiple UvrDΔ40C molecules jointly participated in DNA unwinding, presumably by forming an oligomer. Thus, the single-molecule observation addressed how the C-terminal amino acids affect the number of helicases bound to DNA, oligomerization, and unwinding activity, which can be applied to other helicases.


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