scholarly journals Pyridoxal phosphate binding to wild type, W330F, and C298S mutants ofEscherichia coliapotryptophanase: unraveling the cold inactivation

FEBS Letters ◽  
1998 ◽  
Vol 433 (3) ◽  
pp. 279-282 ◽  
Author(s):  
Tali Erez ◽  
Robert S. Phillips ◽  
Abraham H. Parola
Keyword(s):  
Pyridoxal Phosphate ◽  
Wild Type ◽  
Phosphate Binding ◽  
Cold Inactivation

scholarly journals Identification of the Enterococcus faecalis Tyrosine Decarboxylase Operon Involved in Tyramine Production

2002 ◽  
Vol 68 (7) ◽  
pp. 3537-3544 ◽  
Author(s):  
Nathalie Connil ◽  
Yoann Le Breton ◽  
Xavier Dousset ◽  
Yanick Auffray ◽  
Alain Rincé ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
High Performance ◽  
Pyridoxal Phosphate ◽  
Trna Synthetase ◽  
Tyrosine Decarboxylase ◽  
Wild Type ◽  
Phosphate Binding ◽  
Gene Encoding ◽  
Reverse Transcription Pcr ◽  
The Family

ABSTRACT Screening of a library of Enterococcus faecalis insertional mutants allowed isolation of a mutant affected in tyramine production. The growth of this mutant was similar to that of the wild-type E. faecalis JH2-2 strain in Maijala broth, whereas high-performance liquid chromatography analyses showed that tyramine production, which reached 1,000 μg ml−1 for the wild-type strain, was completely abolished. Genetic analysis of the insertion locus revealed a gene encoding a decarboxylase with similarity to eukaryotic tyrosine decarboxylases. Sequence analysis revealed a pyridoxal phosphate binding site, indicating that this enzyme belongs to the family of amino acid decarboxylases using this cofactor. Reverse transcription-PCR analyses demonstrated that the gene (tdc) encoding the putative tyrosine decarboxylase of E. faecalis JH2-2 is cotranscribed with the downstream gene encoding a putative tyrosine-tyramine antiporter and with the upstream tyrosyl-tRNA synthetase gene. This study is the first description of a tyrosine decarboxylase gene in prokaryotes.

scholarly journals Gene Cloning and Molecular Characterization of Lysine Decarboxylase from Selenomonas ruminantiumDelineate Its Evolutionary Relationship to Ornithine Decarboxylases from Eukaryotes

2000 ◽  
Vol 182 (23) ◽  
pp. 6732-6741 ◽  
Author(s):  
Yumiko Takatsuka ◽  
Yoshihiro Yamaguchi ◽  
Minenobu Ono ◽  
Yoshiyuki Kamio
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Pyridoxal Phosphate ◽  
Evolutionary Relationship ◽  
Binding Domain ◽  
Sequencing Analysis ◽  
Lysine Decarboxylase ◽  
Amino Acid Residues ◽  
Phosphate Binding ◽  
Link Type

ABSTRACT Lysine decarboxylase (LDC; EC 4.1.1.18 ) from Selenomonas ruminantium comprises two identical monomeric subunits of 43 kDa and has decarboxylating activities toward both l-lysine andl-ornithine with similar Km andVmax values (Y. Takatsuka, M. Onoda, T. Sugiyama, K. Muramoto, T. Tomita, and Y. Kamio, Biosci. Biotechnol. Biochem. 62:1063–1069, 1999). Here, the LDC-encoding gene (ldc) of this bacterium was cloned and characterized. DNA sequencing analysis revealed that the amino acid sequence of S. ruminantium LDC is 35% identical to those of eukaryotic ornithine decarboxylases (ODCs; EC 4.1.1.17 ), including the mouse,Saccharomyces cerevisiae, Neurospora crassa,Trypanosoma brucei, and Caenorhabditis elegansenzymes. In addition, 26 amino acid residues, K69, D88, E94, D134, R154, K169, H197, D233, G235, G236, G237, F238, E274, G276, R277, Y278, K294, Y323, Y331, D332, C360, D361, D364, G387, Y389, and F397 (mouse ODC numbering), all of which are implicated in the formation of the pyridoxal phosphate-binding domain and the substrate-binding domain and in dimer stabilization with the eukaryotic ODCs, were also conserved inS. ruminantium LDC. Computer analysis of the putative secondary structure of S. ruminantium LDC showed that it is approximately 70% identical to that of mouse ODC. We identified five amino acid residues, A44, G45, V46, P54, and S322, within the LDC catalytic domain that confer decarboxylase activities toward bothl-lysine and l-ornithine with a substrate specificity ratio of 0.83 (defined as thek cat/Km ratio obtained with l-ornithine relative to that obtained withl-lysine). We have succeeded in converting S. ruminantium LDC to form with a substrate specificity ratio of 58 (70 times that of wild-type LDC) by constructing a mutant protein, A44V/G45T/V46P/P54D/S322A. In this study, we also showed that G350 is a crucial residue for stabilization of the dimer in S. ruminantium LDC.

Effect of substitution of a pyridoxal phosphate-binding lysyl residue of thermostable D-amino acid aminotransferase by arginine and alanine

Biochemistry ◽  
1991 ◽  
Vol 30 (16) ◽  
pp. 4072-4077 ◽  
Author(s):  
Katsushi Nishimura ◽  
Katsuyuki Tanizawa ◽  
Tohru Yoshimura ◽  
Nobuyoshi Esaki ◽  
Shiroh Futaki ◽  
...  
Keyword(s):  
Amino Acid ◽  
Pyridoxal Phosphate ◽  
Phosphate Binding ◽  
Lysyl Residue

scholarly journals Role of βAsn-243 in the Phosphate-binding Subdomain of Catalytic Sites ofEscherichia coliF1-ATPase

2004 ◽  
Vol 279 (44) ◽  
pp. 46057-46064 ◽  
Author(s):  
Zulfiqar Ahmad ◽  
Alan E. Senior
Keyword(s):  
Atpase Activity ◽  
Atp Synthase ◽  
Catalytic Mechanism ◽  
Wild Type ◽  
Phosphate Binding ◽  
Γ Subunit ◽  
Catalytic Sites ◽  
The Face ◽  
Extensive Involvement

In the catalytic mechanism of ATP synthase, phosphate (Pi) binding and release steps are believed to be correlated to γ-subunit rotation, and Pibinding is proposed to be prerequisite for binding ADP in the face of high cellular [ATP]/[ADP] ratios. In x-ray structures, residue βAsn-243 appears centrally located in the Pi-binding subdomain of catalytic sites. Here we studied the role of βAsn-243 inEscherichia coliATP synthase by mutagenesis to Ala and Asp. Mutation βN243A caused 30-fold impairment of F1-ATPase activity; 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole inhibited this activity less potently than in wild type and Piprotected from inhibition. ADP-fluoroaluminate was more inhibitory than in wild-type, but ADP-fluoroscandium was less inhibitory. βN243D F1-ATPase activity was impaired by 1300-fold and was not inhibited by ADP-fluoroaluminate or ADP-fluoroscandium. 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole activated βN243D F1-ATPase, and Pidid not affect activation. We conclude that residue βAsn-243 is not involved in Pibinding directly but is necessary for correct organization of the transition state complex through extensive involvement in hydrogen bonding to neighboring residues. It is also probably involved in orientation of the “attacking water” and of an associated second water.

Immunoblot detection of pyridoxal phosphate binding proteins in liver and hepatoma cytosolic extracts

1983 ◽  
Vol 112 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Jason M. Kittler ◽  
Dace Viceps-Madore ◽  
John A. Cidlowski ◽  
John W. Thanassi
Keyword(s):  
Binding Proteins ◽  
Pyridoxal Phosphate ◽  
Phosphate Binding
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