Biomaterial Database

Cloning and expression of the genetically unstable tyrosinase structural gene from Streptomyces glaucescens. 1985

G Hintermann, and M Zatchej, and R Hütter

The gene from Streptomyces glaucescens coding for an inducible tyrosinase was cloned using the low copy vector pIJ41 and the melanin-negative strain Streptomyces lividans TK23 as host. Hybridisation experiments as well as complementation studies showed that melC mutant strains carry large deletions of more than 10.5 kb, comprising the structural gene for tyrosinase, while melA and melB strains carry mutations in genes involved in the expression of tyrosinase activity. Strong DNA homology was found between the Streptomyces antibioticus and the S. glaucescens tyrosinase structural genes and both genes showed a similar regulation when introduced into melanin-negative hosts. While both tyrosinases exhibited clear induction in S. glaucescens, constitutive expression was observed in S. lividans. Northern blot experiments showed that tyrosinase expression is regulated at the transcriptional level and that the gene (822 bp) is part of a 2.3 kb transcript. The main start of the mRNA at about 475 bp upstream from the tyrosinase N-terminus was located by S1-mapping experiments.

UI	MeSH Term	Description	Entries
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004156	Catechol Oxidase	An enzyme of the oxidoreductase class that catalyzes the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. EC 1.10.3.1.	Diphenol Oxidases,Diphenol Oxidase,Polyphenol Oxidase,Polyphenoloxidase,Oxidase, Catechol,Oxidase, Diphenol,Oxidase, Polyphenol,Oxidases, Diphenol
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
D005798	Genes, Bacterial	The functional hereditary units of BACTERIA.	Bacterial Gene,Bacterial Genes,Gene, Bacterial
D005838	Genotype	The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.	Genogroup,Genogroups,Genotypes
D013291	Streptococcus	A genus of gram-positive, coccoid bacteria whose organisms occur in pairs or chains. No endospores are produced. Many species exist as commensals or parasites on man or animals with some being highly pathogenic. A few species are saprophytes and occur in the natural environment.
D014442	Monophenol Monooxygenase	An enzyme of the oxidoreductase class that catalyzes the reaction between L-tyrosine, L-dopa, and oxygen to yield L-dopa, dopaquinone, and water. It is a copper protein that acts also on catechols, catalyzing some of the same reactions as CATECHOL OXIDASE. EC 1.14.18.1.	Dopa Oxidase,Phenoloxidase,Tyrosinase,Cresolase,Phenol Oxidase,Phenoloxidase A,Phenoloxidase B,Monooxygenase, Monophenol,Oxidase, Dopa,Oxidase, Phenol