Abstract
The structural gene (pgk) encoding 3-phosphoglycerate kinase (PGK) from Bacillus stearothermophilus NCA 1503, has been cloned in Escherichia coli and its complete nucleotide sequence determined. The gene consists of an open reading frame corresponding to a protein of 394 amino acids (aa) (calculated M(r) 42 703) and, in common with other prokaryotic pgk genes, is preceded by the structural gene encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Constructs containing the B. stearothermophilus pgk gene and its flanking sequences in the high-copy plasmid, pUC9, co-express both PG K and GA PDH at high levels in transformed E. coli cells, typically producing PGK at levels of up to 30% of the soluble cell protein. The deduced aa sequence of B. stearothermophilus PGK is compared with those of the mesophilic (yeast) and extreme thermophilic (Thermus thermophilus) enzymes since the crystal structure of these PGKs are known or are in the process of being determined. Changes in the sequences of the three enzymes, as they appear to relate to the enhancement of thermal stability, are discussed.
Original language | English |
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Pages (from-to) | 39-45 |
Number of pages | 7 |
Journal | Gene |
Volume | 109 |
Issue number | 1 |
Publication status | Published - 20 Dec 1991 |
Keywords
- RECOMBINANT DNA
- NUCLEOTIDE SEQUENCE
- AMINO ACID SEQUENCE COMPARISONS
- OVEREXPRESSION
- THERMAL STABILITY
- YEAST PHOSPHOGLYCERATE KINASE
- THERMOPHILE THERMUS-THERMOPHILUS
- NUCLEOTIDE-SEQUENCE
- HEAT-STABILITY
- AMINO-ACIDS
- CLONING
- ENZYME
- PROTEINS
- DEHYDROGENASE