Identification and Bioinformatics Analysis of Cysteine Synthase from the Filamentous Fungus, Monascus purpureus

2014 ◽  
Vol 522-524 ◽  
pp. 272-275
Author(s):  
Nan Qing Liao ◽  
Jiang Ning Yao ◽  
Hao Ming Li
Keyword(s):  
Amino Acid ◽  
Pyridoxal Phosphate ◽  
Structural Model ◽  
Bioinformatics Analysis ◽  
Tertiary Structure ◽  
Monascus Purpureus ◽  
Gene Encoding ◽  
Cysteine Synthase ◽  
Comparison Results ◽  
Alignment Analysis

A gene encoding a putative cysteine synthase was obtained by screening Monascus purpureus cDNA library. Bioinformatics analysis showed that this protein has Rhodanese Homology Domain in C-terminal, and Pyridoxal-phosphate dependent enzyme domain in N-terminal, and CBS-like structure. The deduced cysteine synthase protein of M. purpureus contained 517 amino acid, with molecular mass of 57,044Da. Sequence alignment analysis revealed that M. purpureus deduced cysteine synthase was closely related to cysteine synthase from Aspergillus, Ajellomyces and Paracoccidioides, and highly homologous to aforementioned and other known cysteine synthase. The structural model of the deduced cysteine synthase closely match the template with 100% confidence and 20-30% identity. The consistency of the comparison results of the primary structure, secondary structure and tertiary structure suggests that the dedued protein may well be cysteine synthase.

Characterization and Bioinformatics Analysis of C-4 Sterol Methyl Oxidase from Monascus purpureus

2014 ◽  
Vol 522-524 ◽  
pp. 247-250
Author(s):  
Jiang Ning Yao ◽  
Nan Qing Liao ◽  
Hao Ming Li
Keyword(s):  
Primary Structure ◽  
Bioinformatics Analysis ◽  
Monascus Purpureus ◽  
Transmembrane Helices ◽  
Gene Encoding ◽  
Fatty Acid Hydroxylase ◽  
Comparison Results ◽  
Methyl Sterol ◽  
Alignment Analysis ◽  
Hydrophobicity Profile

A gene encoding a putative C-4 sterol methyl oxidase was obtained by screening Monascus purpureus cDNA library. Bioinformatics analysis showed that this protein has a primary structure, a hydrophobicity profile and a pattern of histidine-rich motifs which are typical of C-4 methyl sterol oxidases. The deduced C-4 sterol methyl oxidase protein of M. purpureus contained 259 amino acid, with molecular mass of 30,299Da. Sequence alignment analysis revealed that M. purpureus deduced C-4 sterol methyl oxidase was closely related to C-4 sterol methyl oxidase from Aspergillus, Penicillium and Byssochlamys, and highly homologous to aforementioned and other known C-4 sterol methyl oxidase. The deduced protein is of a membrane protein with two transmembrane helices, which belongs to the fatty acid hydroxylase superfamily. The consistency of the comparison results of the primary structure, secondary structure and physicochemical properties suggests that the dedued protein may well be C-4 sterol methyl oxidase.

scholarly journals Catalytic and Molecular Properties of the Quinohemoprotein Tetrahydrofurfuryl Alcohol Dehydrogenase from Ralstonia eutropha Strain Bo

2001 ◽  
Vol 183 (6) ◽  
pp. 1954-1960 ◽  
Author(s):  
Grit Zarnt ◽  
Thomas Schräder ◽  
Jan R. Andreesen
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Alcohol Dehydrogenase ◽  
Tertiary Structure ◽  
Ralstonia Eutropha ◽  
Signal Sequence ◽  
Substrate Inhibition ◽  
Catalytic Efficiency ◽  
Gene Encoding

ABSTRACT The quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (THFA-DH) from Ralstonia eutropha strain Bo was investigated for its catalytic properties. The apparentk cat/Km andK i values for several substrates were determined using ferricyanide as an artificial electron acceptor. The highest catalytic efficiency was obtained with n-pentanol exhibiting a k cat/Km value of 788 × 104 M−1 s−1. The enzyme showed substrate inhibition kinetics for most of the alcohols and aldehydes investigated. A stereoselective oxidation of chiral alcohols with a varying enantiomeric preference was observed. Initial rate studies using ethanol and acetaldehyde as substrates revealed that a ping-pong mechanism can be assumed for in vitro catalysis of THFA-DH. The gene encoding THFA-DH from R. eutropha strain Bo (tfaA) has been cloned and sequenced. The derived amino acid sequence showed an identity of up to 67% to the sequence of various quinoprotein and quinohemoprotein dehydrogenases. A comparison of the deduced sequence with the N-terminal amino acid sequence previously determined by Edman degradation analysis suggested the presence of a signal sequence of 27 residues. The primary structure of TfaA indicated that the protein has a tertiary structure quite similar to those of other quinoprotein dehydrogenases.

scholarly journals Identification and Biochemical Characterization of Serine Hydroxymethyl Transferase in the Hydrogenosome of Trichomonas vaginalis

2006 ◽  
Vol 5 (12) ◽  
pp. 2072-2078 ◽  
Author(s):  
Mandira Mukherjee ◽  
Stuart A. Sievers ◽  
Mark T. Brown ◽  
Patricia J. Johnson
Keyword(s):  
Amino Acid ◽  
Active Site ◽  
Trichomonas Vaginalis ◽  
Pyridoxal Phosphate ◽  
Biochemical Characterization ◽  
Single Gene ◽  
Mammalian Host ◽  
Gene Encoding ◽  
Conserved Sequence ◽  
Serine Hydroxymethyl Transferase

ABSTRACT Serine hydroxymethyl transferase (SHMT) is a pyridoxal phosphate (PLP)-dependent enzyme that catalyzes the reversible conversion of serine and tetrahydrofolate to glycine and methylenetetrahydrofolate. We have identified a single gene encoding SHMT in the genome of Trichomonas vaginalis, an amitochondriate, deep-branching unicellular protist. The protein possesses a putative N-terminal hydrogenosomal presequence and was shown to localize to hydrogensomes by immunofluorescence analysis, providing evidence of amino acid metabolism in this unusual organelle. In contrast to the tetrameric SHMT that exists in the mammalian host, we found that the T. vaginalis SHMT is a homodimer, as found in prokaryotes. All examined SHMT contain an 8-amino-acid conserved sequence, VTTTTHKT, containing the active-site lysyl residue (Lys 251 in TvSHMT) that forms an internal aldimine with PLP. We mutated this Lys residue to Arg and Gln and examined structural and catalytic properties of the wild-type and mutant enzymes in comparison to that reported for the mammalian protein. The oligomeric structure of the mutant K251R and K251Q TvSHMT was not affected, in contrast to that observed for comparable mutations in the mammalian enzyme. Likewise, contrary to that observed for mammalian SHMT, the catalytic activity of K251R TvSHMT was unaffected in the presence of PLP. The K251Q TvSHMT, however, was found to be inactive. These studies indicate that the active site of the parasite enzyme is distinct from its prokaryotic and eukaryotic counterparts and identify TvSHMT as a potential drug target.

Identification of the gene encoding 3-(5-oxo-2-thioxoimidazolidin-4-yl) propionic acid desulfhydrase in Burkholderia sp. HME13

2020 ◽  
Vol 85 (3) ◽  
pp. 626-629
Author(s):  
Hisashi Muramatsu ◽  
Hiroki Maguchi ◽  
Taisuke Harada ◽  
Takehiro Kashiwagi ◽  
Chul-Sa Kim ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Amino Acid Sequence ◽  
Propionic Acid ◽  
Unknown Function ◽  
Protein Family ◽  
Amino Acid Sequence Analysis ◽  
Gene Encoding

ABSTRACT Here, we report the identification of the gene encoding a novel enzyme, 3-(5-oxo-2-thioxoimidazolidin-4-yl) propionic acid desulfhydrase, in Burkholderia sp. HME13. The enzyme converts 3-(5-oxo-2-thioxoimidazolidin-4-yl) propionic acid and H2O to 3-(2,5-dioxoimidazolidin-4-yl) propionic acid and H2S. Amino acid sequence analysis of the enzyme indicates that it belongs to the DUF917 protein family, which consists of proteins of unknown function.

scholarly journals A Single Point Mutation, Asn16→Lys, Dictates the Temperature-Sensitivity of the Reovirus tsG453 Mutant

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 289
Author(s):  
Kathleen K. M. Glover ◽  
Danica M. Sutherland ◽  
Terence S. Dermody ◽  
Kevin M. Coombs
Keyword(s):  
Amino Acid ◽  
Temperature Sensitivity ◽  
Reverse Genetics ◽  
Core Protein ◽  
Single Point ◽  
Single Amino Acid ◽  
Single Point Mutation ◽  
Temperature Sensitive ◽  
Amino Acid Substitutions ◽  
Gene Encoding

Studies of conditionally lethal mutants can help delineate the structure-function relationships of biomolecules. Temperature-sensitive (ts) mammalian reovirus (MRV) mutants were isolated and characterized many years ago. Two of the most well-defined MRV ts mutants are tsC447, which contains mutations in the S2 gene encoding viral core protein σ2, and tsG453, which contains mutations in the S4 gene encoding major outer-capsid protein σ3. Because many MRV ts mutants, including both tsC447 and tsG453, encode multiple amino acid substitutions, the specific amino acid substitutions responsible for the ts phenotype are unknown. We used reverse genetics to recover recombinant reoviruses containing the single amino acid polymorphisms present in ts mutants tsC447 and tsG453 and assessed the recombinant viruses for temperature-sensitivity by efficiency-of-plating assays. Of the three amino acid substitutions in the tsG453 S4 gene, Asn16-Lys was solely responsible for the tsG453ts phenotype. Additionally, the mutant tsC447 Ala188-Val mutation did not induce a temperature-sensitive phenotype. This study is the first to employ reverse genetics to identify the dominant amino acid substitutions responsible for the tsC447 and tsG453 mutations and relate these substitutions to respective phenotypes. Further studies of other MRV ts mutants are warranted to define the sequence polymorphisms responsible for temperature sensitivity.

Further characterization and determination of the single amino acid change in thetsI138reovirus thermosensitive mutant

2012 ◽  
Vol 58 (5) ◽  
pp. 589-595
Author(s):  
Guy Lemay ◽  
Martin Bisaillon
Keyword(s):  
Amino Acid ◽  
Amino Acid Change ◽  
Genetic Alterations ◽  
Biological Properties ◽  
Single Amino Acid ◽  
Temperature Sensitive ◽  
Nonpermissive Temperature ◽  
Gene Encoding ◽  
Viral Particles ◽  
Single Amino Acid Change

Many temperature-sensitive mutants have been isolated in early studies of mammalian reovirus. However, the biological properties and nature of the genetic alterations remain incompletely explored for most of these mutants. The mutation harbored by the tsI138 mutant was already assigned to the L3 gene encoding the λ1 protein. In the present study, this mutant was further studied as a possible tool to establish the role of the putative λ1 enzymatic activities in viral multiplication. It was observed that synthesis of viral proteins is only marginally reduced, while it was difficult to recover viral particles at the nonpermissive temperature. A single nucleotide substitution resulting in an amino acid change was found; the position of this amino acid is consistent with a probable defect in assembly of the inner capsid at the nonpermissive temperature.

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