scholarly journals Affinity purification of 5-methylthioribose kinase and 5-methylthioadenosine/S-adenosylhomocysteine nucleosidase from Klebsiella pneumoniae

1996 ◽  
Vol 317 (1) ◽  
pp. 285-290 ◽  
Author(s):  
Kenneth A. CORNELL ◽  
R. W. WINTER ◽  
Paula A. TOWER ◽  
Michael K. RISCOE

Two enzymes in the methionine salvage pathway, 5-methylthioribose kinase (MTR kinase) and 5´-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTA/SAH nucleosidase) were purified from Klebsiellapneumoniae. Chromatography using a novel 5´-(p-aminophenyl)thioadenosine/5-(p-aminophenyl)thioribose affinity matrix allowed the binding and selective elution of each of the enzymes in pure form. The molecular mass, substrate kinetics and N-terminal amino acid sequences were characterized for each of the enzymes. Purified MTR kinase exhibits an apparent molecular mass of 46–50 kDa by SDS/PAGE and S200HR chromatography, and has a Km for MTR of 12.2 μM. Homogeneous MTA/SAH nucleosidase displays a molecular mass of 26.5 kDa by SDS/PAGE, and a Km for MTA of 8.7 μM. Comparisons of the N-terminal sequences obtained for each of the enzymes with protein-sequence databases failed to reveal any significant sequence similarities to known proteins. However, the amino acid sequence obtained for the nucleosidase did share a high degree of sequence similarity with the putative translation product of an open reading frame in Escherichia coli, thus providing a tentative identification of this gene as encoding an MTA/SAH nucleosidase.

2001 ◽  
Vol 357 (2) ◽  
pp. 581-586 ◽  
Author(s):  
Karin DENGER ◽  
Jürgen RUFF ◽  
Ulrike REIN ◽  
Alasdair M. COOK

The strictly anaerobic bacterium Desulfonispora thiosulfatigenes ferments taurine via sulphoacetaldehyde, which is hydrolysed to acetate and sulphite by sulphoacetaldehyde sulpho-lyase (EC 4.4.1.12). The lyase was expressed at high levels and a two-step, 4.5-fold purification yielded an apparently homogeneous soluble protein, which was presumably a homodimer in its native form; the molecular mass of the subunit was about 61kDa (by SDS/PAGE). The mass was determined to be 63.8kDa by matrix-assisted laser-desorption ionization–time-of-flight (MALDI–TOF) MS. The purified enzyme converted 1mol of sulphoacetaldehyde to 1mol each of sulphite and acetate, but no requirement for thiamine pyrophosphate (TPP) was detected. The N-terminal and two internal amino acid sequences were determined, which allowed us to generate PCR primers. The gene was amplified and sequenced. The DNA sequence had no significant homologue in the databases searched, whereas the derived amino acid sequence indicated an oxo-acid lyase, revealed a TPP-binding site and gave a derived molecular mass of 63.8kDa.


1996 ◽  
Vol 316 (2) ◽  
pp. 685-690 ◽  
Author(s):  
Masahiro TAMOI ◽  
Takahiro ISHIKAWA ◽  
Toru TAKEDA ◽  
Shigeru SHIGEOKA

NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been purified to electrophoretic homogeneity from Synechococcus PCC 7942 cells. The native enzyme had a molecular mass of 160 kDa and consisted of four subunits with a molecular mass of 41 kDa. The activity was 6-fold higher with NADPH than with NADH; the apparent Km values for NADPH and NADH were 62±4.5 and 420±10.5 μM respectively. The gene encoding NADP-dependent GAPDH was cloned from the chromosomal DNA of Synechococcus 7942. A 1140 bp open reading frame, encoding an enzyme of 380 amino acid residues (approx. molecular mass of 41.3 kDa) was observed. The deduced amino acid sequence of the gene had a greater sequence similarity to the NADP-dependent and chloroplastic form than to the NAD-dependent and cytosolic form. The Synechococcus 7942 enzyme lacked one of the cysteines involved in the light-dependent regulation of the chloroplast enzymes of higher plants. The recombinant enzyme expressed in Escherichia coli as well as the native enzyme purified from Synechococcus 7942 cells were resistant to 1 mM H2O2.


2003 ◽  
Vol 69 (7) ◽  
pp. 3849-3857 ◽  
Author(s):  
Takako Mukai ◽  
Shigeyuki Kawai ◽  
Hirokazu Matsukawa ◽  
Yuhsi Matuo ◽  
Kousaku Murata

ABSTRACT A bacterium exhibiting activities of several inorganic polyphosphate [poly(P)]- and ATP-dependent kinases, including glucokinase, NAD kinase, mannokinase, and fructokinase, was isolated, determined to belong to the genus Arthrobacter, and designated Arthrobacter sp. strain KM. Among the kinases, a novel enzyme responsible for the poly(P)- and ATP-dependent mannokinase activities was purified 2,200-fold to homogeneity from a cell extract of the bacterium. The purified enzyme was a monomer with a molecular mass of 30 kDa. This enzyme phosphorylated glucose and mannose with a high affinity for glucose, utilizing poly(P) as well as ATP, and was designated poly(P)/ATP-glucomannokinase. The K m values of the enzyme for glucose, mannose, ATP, and hexametaphosphate were determined to be 0.50, 15, 0.20, and 0.02 mM, respectively. The catalytic sites for poly(P)-dependent phosphorylation and ATP-dependent phosphorylation of the enzyme were found to be shared, and the poly(P)-utilizing mechanism of the enzyme was shown to be nonprocessive. The gene encoding the poly(P)/ATP-glucomannokinase was cloned from Arthrobacter sp. strain KM, and its nucleotide sequence was determined. This gene contained an open reading frame consisting of 804 bp coding for a putative polypeptide with a calculated molecular mass of 29,480 Da. The deduced amino acid sequence of the polypeptide exhibited homology to the amino acid sequences of the poly(P)/ATP-glucokinase of Mycobacterium tuberculosis H37Rv (level of homology, 45%), ATP-dependent glucokinases of Corynebacterium glutamicum (45%), Renibacterium salmoninarum (45%), and Bacillus subtilis (35%), and proteins of bacteria belonging to the order Actinomyces whose functions are not known. Alignment of these homologous proteins revealed seven conserved regions. The mannose and poly(P) binding sites of poly(P)/ATP-glucomannokinase are discussed.


1999 ◽  
Vol 45 (6) ◽  
pp. 464-471 ◽  
Author(s):  
Joseilde O Silva-Werneck ◽  
Marlene T De-Souza ◽  
José MC de S. Dias ◽  
Bergmann M Ribeiro

A Brazilian strain of Bacillus thuringiensis subsp. kurstaki, designated S93, was analyzed regarding its cry gene and protein contents and activity against the fall armyworm (Spodoptera frugiperda, Smith 1797). Bioassays using lyophilized powders of S93 or HD-1 and third instar larvae of S. frugiperda showed a 12.3-fold lower LC50for the S93 strain when compared with the standard HD-1 strain. The spore-crystal mixture, analyzed by SDS-PAGE, showed two major polypeptides of 130 and 65 kDa, corresponding to Cry1 and Cry2 toxins, respectively. Western blot analysis showed that these proteins were immunologically related to the Cry1A protein from B. thuringiensis subsp. kurstaki HD-73. The polymerase chain reaction technique (PCR) using total DNA from the S93 strain and specific primers showed the presence of cry1Aa, cry1Ab, and cry1Ac genes, and a cry1A-type gene was localized in a plasmid of about 44 MDa. A cry1Ab gene was isolated from a S93 plasmid DNA library and completely sequenced. Computer analysis showed that the gene sequence (GenBank acession number AF059670) is identical to cry1Ab1 and has 91.6 and 85.9% identity with cry1Aa1 and cry1Ac1 genes, respectively. The deduced amino-acid sequence showed a high degree of similarity with the amino-acid sequences of the Cry1Ab1 (100%), Cry1Aa1 (93.8%), and Cry1Ac1 (90.6%) proteins.Key words: Bacillus thuringiensis, Spodoptera frugiperda, biological control, crystal protein, cry genes.


1995 ◽  
Vol 311 (3) ◽  
pp. 951-957 ◽  
Author(s):  
B Berger ◽  
P E Hunziker ◽  
C R Hauer ◽  
N Birchler ◽  
R Dallinger

1. Two cadmium-binding metallothionein (Mt) isoforms, called Mta and Mtb, were isolated from terrestrial snails (Arianta arbustorum), using various chromatographic techniques, such as gel-permeation chromatography and reversed-phase HPLC. The purified proteins were S-methylated and cleaved by means of different enzymes (trypsin, endoproteinase Glu-C, and endoproteinase Asp-N). Amino acid sequences were determined by automated Edman degradation and collision-induced dissociation (CID) tandem MS. According to their primary structures, both isoforms should be attributed to class-I Mts. 2. The two forms are structurally identical, differing only by one amino acid exchange in position 60 of the peptide chain. Both isoproteins consist of 66 amino acids, 18 of which are cysteine residues. Most of the cysteine residues are arranged in seven Cys-Xaa-Cys motifs. Mta and Mtb possess an N-terminal acetylated-serine residue and contain a short N-terminal motif which shows a high degree of similarity with the N-termini of histones H4 and H2A. 3. A comparison of Mta and Mtb with other invertebrate Mts shows a very high degree of sequence similarity with a cadmium-binding Mt from Helix pomatia, a species that is closely related to Arianta arbustorum. Moreover, Mta and Mtb, as expected, also exhibit structural similarities with Mts from other molluscan species, such as mussels and oysters. It is suggested that Mta and Mtb represent two allelic isoforms, reflecting the genetic polymorphism of Mt in Arianta arbustorum.


1993 ◽  
Vol 294 (2) ◽  
pp. 387-390 ◽  
Author(s):  
L C Au ◽  
S B Lin ◽  
J S Chou ◽  
G W Teh ◽  
K J Chang ◽  
...  

The 1.54 kb cDNA for ancrod, a thrombin-like enzyme, was cloned from a lambda ZAP cDNA library derived from the venom glands of Calloselasma (Agkistrodon) rhodostoma. The cDNA sequence reveals that ancrod is synthesized as a pre-zymogen of 258 amino acids, including a putative secretory peptide of 18 amino acids and a proposed zymogen peptide of 6 amino-acid residues. The amino-acid sequence of the predicted active form of the enzyme exhibits a high degree of sequence similarity to those of mammalian serine proteases (trypsin and pancreatic kallikrein) and other thrombin-like enzymes (batroxobin and flavoxobin). Key amino-acid residues (His43, Asp88, Ser182 and Asp176) that are thought to be involved in the substrate cleavage and in the substrate-binding reaction are conserved. Ancrod contains 13 cysteine residues. Based on alignment with the amino-acid sequences of trypsin and batroxobin, six disulphide bridges can be predicted to be present in the ancrod protein. The existence of a free cysteine, which changes the common sequence surrounding the Ser182 active site from Gly-Asp-Ser-Gly-Gly-Pro to Cys-Asp-Ser-Gly-Gly-Pro, is unusual for a serine protease.


2001 ◽  
Vol 82 (11) ◽  
pp. 2641-2645 ◽  
Author(s):  
Jin-an Huang ◽  
Nino Ficorilli ◽  
Carol A. Hartley ◽  
Rebbecca S. Wilcox ◽  
Marianne Weiss ◽  
...  

Equine rhinovirus serotype 3 isolate P313/75 was assigned, with an unclassified genus status, to the family Picornaviridae. The sequence from the 5′ poly(C) tract to the 3′ poly(A) tract of P313/75 was determined. The sequence is 8821 bases in length and contains a potential open reading frame for a polyprotein of 2583 amino acids. Sequence comparison and phylogenic analysis suggest that P313/75 is most closely related to the prototype equine rhinitis B virus (ERBV) strain P1436/71, formerly named equine rhinovirus type 2. A high degree of sequence similarity was found in the P2 and P3 regions of the two genomes. However, the deduced amino acid sequences of the P1 region of P313/75 and ERBV strain P1436/71 contained significant differences, which presumably account for the serological segregation of the two viruses. It is suggested that P313/75 can be classified as a new serotype of the genus Erbovirus, tentatively named ERBV2. Seroepidemiological data indicate that ERBV2 infection of horses may be common (24%) in Australia.


1996 ◽  
Vol 319 (2) ◽  
pp. 499-506 ◽  
Author(s):  
Chan K. N. CHION CHAN KWO ◽  
David J LEAK

Epoxypropane isomerase from Xanthobacter Py2 has been resolved into at least two components (A and B) by ion-exchange chromatography. Both components were required for the degradation of epoxypropane and were purified further. Component A was apparently homohexameric with a subunit Mr of about 44000, and possessed NAD+-dependent dihydrolipoamide dehydrogenase activity and lipoamide reductase activity. It was sensitive to inhibition by o-phenanthroline and the thiol-specific reagents N-ethylmaleimide (NEM) and p-chloromercuribenzoate. Component B was homodimeric with a subunit Mr of 62170 and contained 2 mol·mol-1 FAD. It had an NADPH-dependent lipoamide reductase activity which was sensitive to NEM and p-chloromercuribenzoate. The N-terminal amino acid sequences and monomer sizes of components A and B correspond to those of ORF1 and ORF3 respectively (ORF = open reading frame) of a recently published sequence of a clone which complements mutants unable to degrade epoxypropane. NADPH was found to replace the need for a low-Mr fraction in epoxypropane degradation assays containing components A and B and NAD+. The predicted amino acid sequence of component A (ORF1) has been analysed and shown to contain a potential ADP binding site near the N-terminus and a putative cofactor binding domain near the C-terminus, with sequence similarity to the biotinyl and lipoyl binding domains of biotin-dependent carboxylases and 2-oxoacid dehydrogenases respectively. A reaction mechanism for epoxypropane degradation, incorporating recent evidence for combined isomerization and carboxylation to acetoacetate, is discussed.


2021 ◽  
Author(s):  
Liying Sun ◽  
Ziqian Lian ◽  
Subha Das ◽  
Jingxian Luo ◽  
Ida Bagus Andika

Abstract In this study, we describe the full-length genome sequence of a novel ourmia-like mycovirus, tentatively designated Botryosphaeria dothidea ourmia-like virus 1 (BdOLV1), isolated from the phytopathogenic fungus, Botryosphaeria dothidea strain P8, associated with apple ring rot in Shanxi province, China. The complete BdOLV1 genome is comprised of 2797 nucleotides, a positive-sense (+) single-stranded RNA (ssRNA) with a single open reading frame (ORF). The ORF putatively encodes a 642-amino acid polypeptide with conserved RNA-dependent RNA polymerase (RdRp) motifs, related to viruses of the family Botourmiaviridae. Phylogenetic analysis based on the RdRp amino acid sequences showed that BdOLV1 is grouped with oomycete-infecting unclassified viruses closely related to the genus Botoulivirus in Botourmiaviridae. This is the first report of a novel (+)ssRNA virus in B. dothidea related to the genus Botoulivirus in the family Botourmiaviridae.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


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