Biomaterial Database

Glucoamylases G1 and G2 from Aspergillus niger are synthesized from two different but closely related mRNAs. 1984

E Boel, and I Hjort, and B Svensson, and F Norris, and K E Norris, and N P Fiil

By the use of glucoamylase-specific synthetic oligodeoxyribonucleotides and molecular cloning of cDNA synthesized from Aspergillus niger total poly(A) + RNA, the primary structure of the glucoamylase G1 mRNA was determined. Glucoamylase G1 is synthesized as a precursor of 640 amino acid residues containing a putative signal peptide of 18 residues, a short propeptide of six residues and the 616 residues long mature enzyme. In vitro translations of mRNA and immunoprecipitations with glucoamylase-specific antisera showed that two glucoamylase polypeptides are synthesized. The larger form with an apparent mol. wt. of 71 000 corresponds to the precursor of glucoamylase G1, and the shorter form with an apparent mol. wt. of 61 000 corresponds to the precursor of glucoamylase G2. From the nucleotide sequencing data of several glucoamylase-specific cDNA recombinants it is shown that the G1 mRNA contains a 169 bp long intervening sequence that can be spliced out to generate a G2 mRNA. Only the 3' part of the G1 mRNA is modified by this splicing event. This kind of differential mRNA processing to give different protein products from one primary transcript has previously only been demonstrated in higher eukaryotes.

UI	MeSH Term	Description	Entries
D011061	Poly A	A group of adenine ribonucleotides in which the phosphate residues of each adenine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.	Adenine Polynucleotides,Polyadenylic Acids,Poly(rA),Polynucleotides, Adenine
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
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
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
D005087	Glucan 1,4-alpha-Glucosidase	An enzyme that catalyzes the hydrolysis of terminal 1,4-linked alpha-D-glucose residues successively from non-reducing ends of polysaccharide chains with the release of beta-glucose. It is also able to hydrolyze 1,6-alpha-glucosidic bonds when the next bond in sequence is 1,4.	1,4-alpha-Glucosidase, Exo,Amyloglucosidase,Exo-1,4-alpha-Glucosidase,Glucoamylase,gamma-Amylase,Glucoamylase G1,Glucoamylase G2,1,4-alpha-Glucosidase, Glucan,Exo 1,4 alpha Glucosidase,Glucan 1,4 alpha Glucosidase,gamma Amylase
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
D005800	Genes, Fungal	The functional hereditary units of FUNGI.	Fungal Genes,Fungal Gene,Gene, Fungal
D005959	Glucosidases	Enzymes that hydrolyze O-glucosyl-compounds. (Enzyme Nomenclature, 1992) EC 3.2.1.-.	Glucosidase
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001234	Aspergillus niger	An imperfect fungus causing smut or black mold of several fruits and vegetables such as grapes, apricots, onions, and peanuts, and is a common contaminant of food.	Aspergillus lacticoffeatus