alpha. -Amylase of Clostridium thermosulfurogenes EM1: Nucleotide sequence of the gene, processing of the enzyme, and comparison to other. alpha. -amylases

Journal Article · Wed May 01 00:00:00 EDT 1991 · Applied and Environmental Microbiology; (United States)

OSTI ID:5410797

Bahl, H; Burchhardt, G; Spreinat, A; Haeckel, K; Wienecke, A; Antranikian, G; Schmidt, B ^[1]

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1. Georg-August-Univ., Gottingen (Germany)

The nucleotide sequence of the {alpha}-amylase gene (amyA) from Clostridium thermosulfurogenes EM1 cloned in Escherichia coli was determined. The reading frame of the gene consisted of 2,121 bp. Comparison of the DNA sequence data with the amino acid sequence of the N terminus of the purified secreted protein of C. thermosulfurogenes Em1 suggested that the {alpha}-amylase is translated form mRNA as a secretory precursor with a signal peptide of 27 amino acid residues. The deduced amino acid sequence of the mature {alpha}-amylase contained 679 residues, resulting in a protein with a molecular mass of 75,112 Da. In E. coli the enzyme was transported to the periplasmic space and the signal peptide was cleaved at exactly the same site between two alanine residues. Comparison of the amino acid sequence of the C. thermosulfurogenes EM1 {alpha}-amylase with those from other bacterial and eukaryotic {alpha}-amylases showed several homologous regions, probably in the enzymatically functioning regions. The tentative Ca{sup 2+}-binding site (consensus region I) of this Ca{sub 2+}-independent enzyme showed only limited homology. The deduced amino acid sequence of a second obviously truncated open reading frame showed significant homology to the malG gene product of E. coli. Comparison of the {alpha}-amylase gene region of C. thermosulfurogenes EM1 (DSM3896) with the {beta}-amylase gene region of C. thermosulfurogenes (ATCC 33743) indicated that both genes have been exchanged with each other at identical sites in the chromosomes of these strains.

• OSTI ID: 5410797
• Journal Information: Applied and Environmental Microbiology; (United States), Vol. 57:5; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AMYLASE
DNA SEQUENCING
CLOSTRIDIUM
MOLECULAR BIOLOGY
AMINO ACID SEQUENCE
DNA-CLONING
GENES
GENETIC ENGINEERING
MESSENGER-RNA
BACTERIA
BIOTECHNOLOGY
CLONING
DNA HYBRIDIZATION
ENZYMES
GLYCOSYL HYDROLASES
HYBRIDIZATION
HYDROLASES
MICROORGANISMS
MOLECULAR STRUCTURE
NUCLEIC ACIDS
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
RNA
STRUCTURAL CHEMICAL ANALYSIS
550200* - Biochemistry