scholarly journals Triphenylmethane Reductase from Citrobacter sp. Strain KCTC 18061P: Purification, Characterization, Gene Cloning, and Overexpression of a Functional Protein in Escherichia coli

2005 ◽  
Vol 71 (12) ◽  
pp. 7955-7960 ◽  
Author(s):  
Moon-Sun Jang ◽  
Young-Mi Lee ◽  
Cheorl-Ho Kim ◽  
Jai-Heon Lee ◽  
Dong-Woo Kang ◽  
...  

ABSTRACT We purified to homogeneity an enzyme from Citrobacter sp. strain KCTC 18061P capable of decolorizing triphenylmethane dyes. The native form of the enzyme was identified as a homodimer with a subunit molecular mass of about 31 kDa. It catalyzes the NADH-dependent reduction of triphenylmethane dyes, with remarkable substrate specificity related to dye structure. Maximal enzyme activity occurred at pH 9.0 and 60°C. The enzymatic reaction product of the triphenylmethane dye crystal violet was identified as its leuco form by UV-visible spectral changes and thin-layer chromatography. A gene encoding this enzyme was isolated based on its N-terminal and internal amino acid sequences. The nucleotide sequence of the gene has a single open reading frame encoding 287 amino acids with a predicted molecular mass of 30,954 Da. Although the deduced amino acid sequence displays 99% identity to the hypothetical protein from Listeria monocytogenes strain 4b H7858, it shows no overall functional similarity to any known protein in the public databases. At the N terminus, the amino acid sequence has high homology to sequences of NAD(P)H-dependent enzymes containing the dinucleotide-binding motif GXXGXXG. The enzyme was heterologously expressed in Escherichia coli, and the purified recombinant enzyme showed characteristics similar to those of the native enzyme. This is the first report of a triphenylmethane reductase characterized from any organism.

2002 ◽  
Vol 76 (11) ◽  
pp. 5829-5834 ◽  
Author(s):  
Yoshio Mori ◽  
Mohammed Ali Borgan ◽  
Naoto Ito ◽  
Makoto Sugiyama ◽  
Nobuyuki Minamoto

ABSTRACT Avian rotavirus NSP4 glycoproteins expressed in Escherichia coli acted as enterotoxins in suckling mice, as did mammalian rotavirus NSP4 glycoproteins, despite great differences in the amino acid sequences. The enterotoxin domain of PO-13 NSP4 exists in amino acid residues 109 to 135, a region similar to that reported in SA11 NSP4.


1992 ◽  
Vol 288 (2) ◽  
pp. 649-655 ◽  
Author(s):  
N Ioannidis ◽  
C E Cooper ◽  
R K Poole

The Escherichia coli haemoglobin-like flavohaemoprotein (Hmp) has been purified to near homogeneity using two chromatographic steps. The prosthetic groups are identified as FAD and protohaem IX. SDS/PAGE has indicated a molecular mass of 44 kDa for the monomeric protein consistent with the amino-acid sequence deduced from the hmp+ gene. The protein, as isolated, is in the Fe(III) state, exhibiting absorbance maxima at 403.5, 540 (shoulder) and 627 nm. The ferrous and carbonmonoxyferrous states resemble those of haemoglobin, showing maxima at 431.5 and 558 nm, and 421, 542 and 566 nm respectively. Upon aerobic addition of NAD(P)H, the ferric state is reduced to the oxygenated Fe(II) state, characterized by maxima at 413, 544 and 580 nm. This oxy form is not stable and slowly decays to the ferric state. Addition of dithionite and nitrite to the ferric protein results in the formation of a nitrosyl complex, whose e.p.r. characteristics indicate that the b-type haem is attached to the protein through a nitrogenous ligand, probably originating from a histidine residue.


1992 ◽  
Vol 284 (3) ◽  
pp. 795-802 ◽  
Author(s):  
J Lu ◽  
A C Willis ◽  
K B M Reid

Human pulmonary surfactant protein D (SP-D) was identified in lung lavage by its similarity to rat SP-D in both its molecular mass and its Ca(2+)-dependent-binding affinity for maltose [Persson, Chang & Crouch (1990) J. Biol. Chem. 265, 5755-5760]. For structural studies, human SP-D was isolated from amniotic fluid by affinity chromatography on maltose-Sepharose followed by f.p.l.c. on Superose 6, which showed it to have a molecular mass of approx. 620 kDa in non-dissociating conditions. On SDS/PAGE the human SP-D behaved as a single band of 150 kDa or 43 kDa in non-reducing or reducing conditions respectively. The presence of a high concentration of glycine (22%), hydroxyproline and hydroxylysine in the amino acid composition of human SP-D indicated that it contained collagen-like structure. Collagenase digestion yielded a 20 kDa collagenase-resistant globular fragment which retained affinity for maltose. Use of maltosyl-BSA as a neoglycoprotein ligand in a solid-phase binding assay showed that human SP-D has a similar carbohydrate-binding specificity to rat SP-D, but a clearly distinct specificity from that of other lectins, such as conglutinin, for a range of simple saccharides. Amino acid sequence analysis established the presence of collagen-like Gly-Xaa-Yaa triplets in human SP-D and also provided sequence data from the globular region of the molecule which was used in the synthesis of oligonucleotide probes. Screening of a human lung cDNA library with the oligonucleotide probes, and also with rabbit anti-(human SP-D), allowed the isolation of two cDNA clones which overlap to give the full coding sequence of human SP-D. The derived amino acid sequence indicates that the mature human SP-D polypeptide chain is 355 residues long, having a short non-collagen-like N-terminal section of 25 residues, followed by a collagen-like region of 177 residues and a C-terminal C-type lectin domain of 153 residues. Comparison of the human SP-D and bovine serum conglutinin amino acid sequences indicated that they showed 66% identity despite their marked differences in carbohydrate specificity.


1999 ◽  
Vol 181 (3) ◽  
pp. 991-997 ◽  
Author(s):  
David J. Bergmann ◽  
James A. Zahn ◽  
Alan A. DiSpirito

ABSTRACT The polypeptide and structural gene for a high-molecular-massc-type cytochrome, cytochromec 553O, was isolated from the methanotrophMethylococcus capsulatus Bath. Cytochromec 553O is a homodimer with a subunit molecular mass of 124,350 Da and an isoelectric point of 6.0. The hemec concentration was estimated to be 8.2 ± 0.4 mol of heme c per subunit. The electron paramagnetic resonance spectrum showed the presence of multiple low spin, S = 1/2, hemes. A degenerate oligonucleotide probe synthesized based on the N-terminal amino acid sequence of cytochrome c 553O was used to identify a DNA fragment from M. capsulatusBath that contains occ, the gene encoding cytochrome c 553O. occ is part of a gene cluster which contains three other open reading frames (ORFs). ORF1 encodes a putative periplasmic c-type cytochrome with a molecular mass of 118,620 Da that shows approximately 40% amino acid sequence identity with occand contains nine c-heme-binding motifs. ORF3 encodes a putative periplasmic c-type cytochrome with a molecular mass of 94,000 Da and contains sevenc-heme-binding motifs but shows no sequence homology toocc or ORF1. ORF4 encodes a putative 11,100-Da protein. The four ORFs have no apparent similarity to any proteins in the GenBank database. The subunit molecular masses, arrangement and number of hemes, and amino acid sequences demonstrate that cytochrome c 553O and the gene products of ORF1 and ORF3 constitute a new class of c-type cytochrome.


2000 ◽  
Vol 182 (8) ◽  
pp. 2277-2284 ◽  
Author(s):  
W. Keith Ray ◽  
Gang Zeng ◽  
M. Benjamin Potters ◽  
Aqil M. Mansuri ◽  
Timothy J. Larson

ABSTRACT Rhodaneses catalyze the transfer of the sulfane sulfur from thiosulfate or thiosulfonates to thiophilic acceptors such as cyanide and dithiols. In this work, we define for the first time the gene, and hence the amino acid sequence, of a 12-kDa rhodanese fromEscherichia coli. Well-characterized rhodaneses are comprised of two structurally similar ca. 15-kDa domains. Hence, it is thought that duplication of an ancestral rhodanese gene gave rise to the genes that encode the two-domain rhodaneses. The glpEgene, a member of the sn-glycerol 3-phosphate (glp) regulon of E. coli, encodes the 12-kDa rhodanese. As for other characterized rhodaneses, kinetic analysis revealed that catalysis by purified GlpE occurs by way of an enzyme-sulfur intermediate utilizing a double-displacement mechanism requiring an active-site cysteine. TheKm s for SSO3 2− and CN− were 78 and 17 mM, respectively. The apparent molecular mass of GlpE under nondenaturing conditions was 22.5 kDa, indicating that GlpE functions as a dimer. GlpE exhibited ak cat of 230 s−1. Thioredoxin 1 from E. coli, a small multifunctional dithiol protein, served as a sulfur acceptor substrate for GlpE with an apparentKm of 34 μM when thiosulfate was near itsKm , suggesting that thioredoxin 1 or related dithiol proteins could be physiological substrates for sulfurtransferases. The overall degree of amino acid sequence identity between GlpE and the active-site domain of mammalian rhodaneses is limited (∼17%). This work is significant because it begins to reveal the variation in amino acid sequences present in the sulfurtransferases. GlpE is the first among the 41 proteins in COG0607 (rhodanese-related sulfurtransferases) of the database Clusters of Orthologous Groups of proteins (http://www.ncbi.nlm.nih.gov/COG/ ) for which sulfurtransferase activity has been confirmed.


1998 ◽  
Vol 64 (7) ◽  
pp. 2473-2478 ◽  
Author(s):  
Ashraf A. Khan ◽  
Eungbin Kim ◽  
Carl E. Cerniglia

ABSTRACT Aeromonas trota AK2, which was derived from ATCC 49659 and produces the extracellular pore-forming hemolytic toxin aerolysin, was mutagenized with the transposon mini-Tn5Km1 to generate a hemolysin-deficient mutant, designated strain AK253. Southern blotting data indicated that an 8.7-kb NotI fragment of the genomic DNA of strain AK253 contained the kanamycin resistance gene of mini-Tn5Km1. The 8.7-kb NotI DNA fragment was cloned into the vector pGEM5Zf(−) by selecting for kanamycin resistance, and the resultant clone, pAK71, showed aerolysin activity in Escherichia coli JM109. The nucleotide sequence of the aerA gene, located on the 1.8-kbApaI-EcoRI fragment, was determined to consist of 1,479 bp and to have an ATG initiation codon and a TAA termination codon. An in vitro coupled transcription-translation analysis of the 1.8-kb region suggested that the aerA gene codes for a 54-kDa protein, in agreement with nucleotide sequence data. The deduced amino acid sequence of the aerA gene product ofA. trota exhibited 99% homology with the amino acid sequence of the aerA product of Aeromonas sobria AB3 and 57% homology with the amino acid sequences of the products of the aerA genes of Aeromonas salmonicida 17-2 and A. sobria 33.


2010 ◽  
Vol 192 (23) ◽  
pp. 6160-6171 ◽  
Author(s):  
Cristina L. Marolda ◽  
Bo Li ◽  
Michael Lung ◽  
Mei Yang ◽  
Anna Hanuszkiewicz ◽  
...  

ABSTRACT Wzx belongs to a family of membrane proteins involved in the translocation of isoprenoid lipid-linked glycans, which is loosely related to members of the major facilitator superfamily. Despite Wzx homologs performing a conserved function, it has been difficult to pinpoint specific motifs of functional significance in their amino acid sequences. Here, we elucidate the topology of the Escherichia coli O157 Wzx (WzxEcO157) by a combination of bioinformatics and substituted cysteine scanning mutagenesis, as well as targeted deletion-fusions to green fluorescent protein and alkaline phosphatase. We conclude that WzxEcO157 consists of 12 transmembrane (TM) helices and six periplasmic and five cytosolic loops, with N and C termini facing the cytoplasm. Four TM helices (II, IV, X, and XI) contain polar residues (aspartic acid or lysine), and they may form part of a relatively hydrophilic core. Thirty-five amino acid replacements to alanine or serine were targeted to five native cysteines and most of the aspartic acid, arginine, and lysine residues. From these, only replacements of aspartic acid-85, aspartic acid-326, arginine-298, and lysine-419 resulted in a protein unable to support O-antigen production. Aspartic acid-85 and lysine-419 are located in TM helices II and XI, while arginine-298 and aspartic acid-326 are located in periplasmic and cytosolic loops 4, respectively. Further analysis revealed that the charge at these positions is required for Wzx function since conservative substitutions maintaining the same charge polarity resulted in a functional protein, whereas those reversing or eliminating polarity abolished function. We propose that the functional requirement of charged residues at both sides of the membrane and in two TM helices could be important to allow the passage of the Und-PP-linked saccharide substrate across the membrane.


1989 ◽  
Vol 35 (1) ◽  
pp. 195-199 ◽  
Author(s):  
Makoto Kimura ◽  
Evelyn Arndt ◽  
Tomomitsu Hatakeyama ◽  
Tamiko Hatakeyama ◽  
Junko Kimura

The amino acid sequences of 16 ribosomal proteins from archaebacterium Halobacterium marismortui have been determined by a direct protein chemical method. In addition, amino acid sequences of three proteins, S11, S18, and L25, have been established by DNA sequencing of their genes as well as by protein sequencing. Comparison of their sequences with those of ribosomal proteins from other organisms revealed that proteins S14, S16, S19, and L25 are related to both eukaryotic and eubacterial ribosomal proteins, being more homologous to eukaryotic than eubacterial counterparts, and proteins S12, S15, and L16 are related to only eukaryotic ribosomal proteins. Furthermore, some proteins are found to be similar to only eubacterial proteins, whereas other proteins show no homology to any other known ribosomal proteins. Comparisons of amino acid compositions between halophilic and nonhalophilic ribosomal proteins revealed that halophilic proteins gain asparatic and glutamic acid residues and significantly lose lysine and arginine residues. In addition, halophilic proteins seem to lose isoleucine as compared with Escherichia coli ribosomal proteins.Key words: halobacteria, ribosomal proteins, amino acid sequence.


2001 ◽  
Vol 69 (2) ◽  
pp. 706-711 ◽  
Author(s):  
Tsungda Hsu ◽  
David L. Hutto ◽  
F. Chris Minion ◽  
Richard L. Zuerner ◽  
Michael J. Wannemuehler

ABSTRACT Brachyspira (Serpulina)hyodysenteriae induces a mucohemorrhagic diarrheal disease in pigs. The production of a beta-hemolysin has been considered a major virulence attribute of this organism. Previous reports have failed to correlate a specific cloned gene sequence with a purified beta-hemolytic protein sequence. Thus, questions still remain concerning the structural gene sequence of the hemolysin. To answer this question unequivocally, the beta-hemolytic toxin was purified from extracts of log-phase spirochetes, and the N-terminal amino acid sequence was determined (K-D-V-V-A-N-Q-L-N-I-S-D-K) and compared with the translated sequences of previously cloned genes, tlyAto tlyC. The lack of homology between tlyA totlyC translated sequences and the purified beta-hemolytic toxin sequence resulted in the study that is reported here. A degenerate probe was designed based on the N-terminal amino acid sequence of the purified beta-hemolysin and used to screen a B. hyodysenteriae genomic library. Three overlapping clones were identified, and one was sequenced to reveal an open reading frame coding for a putative 8.93-kDa polypeptide containing the N-terminal sequence of the purified beta-hemolysin. To distinguish this gene from the tlyA to tlyC genes, it has been designatedhlyA. A hemolysis-negative Escherichia colistrains containing hlyA was beta-hemolytic on blood agar media. Also, the hemolytic activity of the recombinant protein had identical protease and lipase sensitivities and electrophoretic mobility to those of native B. hyodysenteriaebeta-hemolysin. Based on sequence analysis, the translated protein had a pI of 4.3, an α-helical structure, and a phosphopantetheine binding motif. Hybridization analysis of genomic DNA indicated that thehlyA gene was present in B. hyodysenteriae andB. intermedia but was not detected in B. innocens, B. pilosicoli, or B. murdochiiunder high-stringency conditions. The location of hlyA on the chromosomal map was distinct from the locations oftlyA, tlyB, and tlyC.


1999 ◽  
Vol 65 (12) ◽  
pp. 5207-5211 ◽  
Author(s):  
Keiko Kita ◽  
Takanobu Fukura ◽  
Koh-Ichi Nakase ◽  
Kenji Okamoto ◽  
Hideshi Yanase ◽  
...  

ABSTRACT We cloned and sequenced the gene encoding an NADPH-dependent aldehyde reductase (ARII) in Sporobolomyces salmonicolorAKU4429, which reduces ethyl 4-chloro-3-oxobutanoate (4-COBE) to ethyl (S)-4-chloro-3-hydroxybutanoate. The ARII gene is 1,032 bp long, is interrupted by four introns, and encodes a 37,315-Da polypeptide. The deduced amino acid sequence exhibited significant levels of similarity to the amino acid sequences of members of the mammalian 3β-hydroxysteroid dehydrogenase–plant dihydroflavonol 4-reductase superfamily but not to the amino acid sequences of members of the aldo-keto reductase superfamily or to the amino acid sequence of an aldehyde reductase previously isolated from the same organism (K. Kita, K. Matsuzaki, T. Hashimoto, H. Yanase, N. Kato, M. C.-M. Chung, M. Kataoka, and S. Shimizu, Appl. Environ. Microbiol. 62:2303–2310, 1996). The ARII protein was overproduced inEscherichia coli about 2,000-fold compared to the production in the original yeast cells. The enzyme expressed inE. coli was purified to homogeneity and had the same catalytic properties as ARII purified from S. salmonicolor. To examine the contribution of the dinucleotide-binding motif G19-X-X-G22-X-X-A25, which is located in the N-terminal region, during ARII catalysis, we replaced three amino acid residues in the motif and purified the resulting mutant enzymes. Substrate inhibition of the G19→A and G22→A mutant enzymes by 4-COBE did not occur. The A25→G mutant enzyme could reduce 4-COBE when NADPH was replaced by an equimolar concentration of NADH.


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