Abstract: It is thought that applications and use of tetrahydrobiopterin (BH4), which is used as a pharmaceutical, will expand due to its superior efficacy. However, in addition to BH4 being extremely expensive, since it is unstable with respect to oxidation, applications other than pharmaceuticals are considered to be difficult. Further, it is difficult for BH4 to permeate through a blood-brain barrier, so that BH4 concentrations in the brain tend not to increase under the present conditions. Biopterins are oxidized form of BH4, stable to oxidation, easy to handle, and can be produced inexpensively. The inventors found that administration of biopterin can be expected to demonstrate effects equal to or greater than those of administration of BH4.

Abstract: Biopterins are useful compounds utilized in pharmaceutical agents or functional foods. The presence of sepiapterin reductase (SPR) involved in the biosynthesis of biopterins has not been confirmed so far in microorganisms except for a few microorganisms such as blue-green algae. For efficiently producing biopterins using microorganisms, it has been demanded to obtain and use SPR genes derived from microorganisms. The present inventors have found that when Saccharomyces cerevisiae or Escherichia coli is transformed with a YIR035C gene from Saccharomyces cerevisiae or a yueD gene from Bacillus subtilis, the transformed microorganism secretes biopterins into a culture solution. Based on this finding, the present invention provides a polypeptide, DNA encoding the polypeptide, a recombinant vector comprising the DNA, and a transformant obtained by transformation with the vector, which are useful in biopterin production using microorganisms.

Abstract: The invention aims at providing a process for producing coenzyme Q10 efficiently in microorganisms by utilizing a coenzyme Q10 side chain synthesis gene derived from a fungal species belonging to the genus Rhodotorula. The present invention relates to a DNA having a DNA sequence described under SEQ ID NO:1, 3 or 5 or derived from the above sequence by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity.

Abstract: The invention aims at providing a process for producing coenzyme Q10 efficiently in microorganisms by utilizing a coenzyme Q10 side chain synthesis gene derived from a fungal species belonging to the genus Aspergillus and genus Leucosporidium. The present invention relates to a DNA having a DNA sequence described under SEQ ID NO:1 and 2 or derived from the above sequence by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity.

Abstract: To provide a method for preparing optically active compounds, which mainly contain (R)-amino compounds, by microbial enzymes efficiently and inexpensively; a polypeptide having stereoselective transaminase activity which can be suitably used for the above preparation method; and a DNA encoding the polypeptide. A method for preparing an optically active amino compound, characterized in stereoselectively transaminating by acting a transaminase on an amino group acceptor, a ketone compound in the presence of an amino group donor, a primary amine; a DNA comprising a nucleotide sequence encoding a polypeptide having stereoselective transaminase activity; and a polypeptide having stereoselective transaminase activity obtainable from a culture of a microorganism belonging to the genus Arthrobacter.

Abstract: The invention aims at providing a process for producing coenzyme Q10 efficiently in microorganisms by utilizing a coenzyme Q10 side chain synthesis gene derived from a fungal species belonging to the genus Aspergillus and genus Leucosporidium.

Abstract: The present invention has for its object to isolate a gene coding for the enzyme synthesizing the coenzyme Q10 side chain from a fungal strain of the genus Saitoella and exploit it to advantage for the efficient microbial production of coenzyme Q10. The present invention provides; a DNA having the nucleotide sequence shown under SEQ ID NO:1 a DNA having a nucleotide sequence derived from the nucleotide sequence of SEQ ID NO:1 by the deletion, addition, insertion and/or substitution of one or a plurality of nucleotides and coding for a protein having decaprenyl diphosphate synthase activity a DNA which hybridizes with the DNA having the nucleotide sequence of SEQ ID NO:1 under a stringent condition and codes for a protein having decaprenyl diphosphate synthase activity.

Abstract: The invention aims at providing a process for producing coenzyme Q10 efficiently in microorganisms by utilizing a coenzyme Q10 side chain synthesis gene derived from a fungal species belonging to the genus Rhodotorula.

Abstract: To provide a method for preparing optically active compounds, which mainly contain (R)-amino compounds, by microbial enzymes efficiently and inexpensively; a polypeptide having stereoselective transaminase activity which can be suitably used for the above preparation method; and a DNA encoding the polypeptide. A method for preparing an optically active amino compound, characterized in stereoselectively transaminating by acting a transaminase on an amino group acceptor, a ketone compound in the presence of an amino group donor, a primary amine; a DNA comprising a nucleotide sequence encoding a polypeptide having stereoselective transaminase activity; and a polypeptide having stereoselective transaminase activity obtainable from a culture of a microorganism belonging to the genus Arthrobacter.

Abstract: A gene of decaprenyl diphosphate synthase, which is the key gene participating in the biosynthesis of coenzyme Q10 was isolated from a bacterium belonging to the family Rhizobiaceae. By transferring this gene into a microorganism such as Escherichia coli and expressing therein, coenzyme Q10 can be effectively produced.

Abstract: Relating to an enzyme capable of efficiently converting a ketone compound to an optically active amino compound by transamination, and a process for preparing an optically active amino compound using the enzyme. An (S)-&agr;-phenethylamine:pyruvate transaminase, which acts on (S)-&agr;-phenethylamine and a ketone compound, thereby catalyzing transamination for forming acetophenone and an amino compound corresponding to the ketone compound; a process for preparing an optically active amino compound using the transaminase; and a method for culturing a microorganism for producing the above transaminase, comprising adding to a medium one or more compounds selected from the group consisting of propylamine, 1-butylamine, 2-butylamine, 2-pentylamine, isopropylamine and isobutylamine as an inducer for the enzyme when a microorganism for producing (S)-&agr;-phenethylamine:pyruvate transaminase is cultured.

Abstract: The method for preparing an optically active (R)-amino compound characterized by the method comprising stereoselectively carrying out amino group transfer by action of an (R)-form-specific transaminase in the co-presence of a ketone compound (amino acceptor), and an amino compound (amino donor) of a racemic form or an (R)-form, to give an optically active (R)-amino compound. According to the present invention, it is made possible to easily prepare at a high yield the optically active (R)-amino compounds and the like having an aryl group and the like at their 1-position, which have been conventionally difficult to prepare.

Abstract: The method for preparing an optically active (R)-amino compound characterized by the method comprising stereoselectively carrying out amino group transfer by action of an (R)-form-specific transaminase in the co-presence of a ketone compound (amino acceptor), and an amino compound (amino donor) of a racemic form or an (R)-form, to give an optically active (R)-amino compound. According to the present invention, it is made possible to easily prepare at a high yield the optically active (R)-amino compounds and the like having an aryl group and the like at their 1-position, which have been conventionally difficult to prepare.

Abstract: The method for preparing an optically active (R)-amino compound characterized by the method comprising stereoselectively carrying out amino group transfer by action of an (R)-form-specific transaminase in the co-presence of a ketone compound (amino acceptor), and an amino compound (amino donor) of a racemic form or an (R)-form, to give an optically active (R)-amino compound. According to the present invention, it is made possible to easily prepare at a high yield the optically active (R)-amino compounds and the like having an aryl group and the like at their 1-position, which have been conventionally difficult to prepare.

Abstract: A DNA fragment coding for a decarbamylase protein improved in thermostability as the result of replacement of at least one base of a DNA fragment coding for a decarbamylase protein derived from a microorganism with another base and the resultant replacement of at least one of the corresponding amino acids, and its production process; a vector containing the DNA fragment; a transformant obtained by transformation with the vector; as well as a decarbamylase improved in thermostability and its production process. Also disclosed is a process for producing a D-.alpha.-amino acid, which comprises converting an N-carbamoyl-D-.alpha.-amino acid into the corresponding D-.alpha.-amino acid in an aqueous medium by the action of a decarbamylase having a thermostable temperature of 65.degree. C. or higher; and collecting the D-.alpha.-amino acid produced.

Abstract: A process for the efficient production of a D-amino acid from the corresponding DL-5-substituted hydantoin by one-step reaction which comprises using a composite immobilized enzyme at a pH about neutrality, said composite immobilized enzyme being obtained by immobilizing a hydantoinase having its optimal pH within an alkaline range and a D-N-carbamyl-.alpha.-amino acid amidohydrolase having its optimal pH about neutrality in a coexisting state on an immobilizing support, simultaneously, is disclosed.

Abstract: In a process for the production of a D-.alpha.-amino acid, in which an N-carbamyl-D-.alpha.-amino acid corresponding to the general formula: ##STR1## wherein R represents phenyl, hydroxy-substituted phenyl, substituted or unsubstituted alkyl, or thienyl, is converted by a microbial enzyme in an aqueous medium to a D-.alpha.-amino acid corresponding to the general formula: ##STR2## wherein R is the same as defined above, decarbamylase produced by a microorganism of the genus Comamonas, Blastobacter, Alcaligenes, Sporosarcina, Rhizobium, Bradyrhizobium or Arthrobacter is used as the enzyme converting the N-carbamyl-D-.alpha.-amino acid to the D-.alpha.-amino acid.The conversion of the N-carbamyl-D-.alpha.-amino acids to the D-.alpha.-amino acids is carried out in a neutral to alkaline pH range.

Abstract: In a process for the production of a D-.alpha.-amino acid, in which an N-carbamyl-D-.alpha.-amino acid corresponding to the general formula: ##STR1## wherein R represents phenyl, hydroxy-substituted phenyl, substituted or unsubstituted alkyl, or thienyl, is converted by a microbial enzyme in an aqueous medium to a D-.alpha.-amino acid corresponding to the general formula: ##STR2## wherein R is the same as defined above, decarbamylase produced by a microorganism of the genus Comamonas, Blastobacter, Alcaligenes, Sporosarcina, Rhizobium, Bradyrhizobium or Arthrobacter is used as the enzyme converting the N-carbamyl-D-.alpha.-amino acid to the D-.alpha.-amino acid.The conversion of the N-carbamyl-D-.alpha.-amino acids to the D-.alpha.-amino acids is carried out in a neutral to alkaline pH range.

Abstract: Decarbamylases are provided capable of producing D-.alpha.-amino acids by hydrolysis of N-carbamyl-D-.alpha.-amino acids. A source of the decarbamylases is recombinant microorganisms produced by gene manipulation methods. Decarbamylases having improved thermostability can be obtained in which amino acids at a thermostability-related site of a natural decarbamylase have been replaced with other amino acids by mutating a DNA fragment encoding the natural decarbamylase. Recombinant DNA is obtained from a vector DNA and a DNA fragment encoding a natural decarbamylase where the nucleic acid sequence encoding an amino acid at a thermostability-related site is replaced with a nucleic acid sequence encoding another amino acid. The recombinant DNA is used to produce transformants that produce thermostable decarbamylases.

Abstract: The present invention is directed to a gene which is related to a D-N-carbamoyl-.alpha.-amino acid amidohydrolase which is an enzyme capable of converting D-N-carbamoyl-.alpha.-amino acids into D-.alpha.-amino acids; a recombinant plasmid in which a DNA fragment containing the gene is incorporated into a vector; a microorganism belonging to the genus Escherichia, Pseudomonas, Flavobacterium, Bacillus, Serratia, Corynebacterium, or Brevibacterium, which is transformed by incorporating the recombinant plasmid thereinto; a process for the production of D-N-carbamoyl-.alpha.-amino acid amidohydrolases, comprising the steps of cultivating the transformed microorganism and collecting the desired product therefrom; a D-N-carbamoyl-.alpha.-amino acid amidohydrolase obtained by the method; and a process for the production of D-.alpha.-amino acids with the aid of an action of the enzyme.The D-N-carbamoyl-.alpha.-amino acid amidohydrolase can be fixed on a support for immobilization and used as an immobilized enzyme.