The role of salt bridges on the temperature adaptation of aqualysin I, a subtilase from the thermophilic bacterium Thermus aquaticus
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چکیده
................................................................................................................................... iii Útdráttur ................................................................................................................................... v Acknowledgement .................................................................................................................... x
منابع مشابه
Substrate Specificity of Aqualysin I, a Bacterial Thermophilic Alkaline Serine Protease from Thermus aquaticus YT-1: Comparison with Proteinase K, Subtilisin BPN' and Subtilisin Carlsberg.
Aqualysin I is the alkaline serine protease isolated from an extreme thermophile, Thermus aquaticus YT-1. We analyzed kinetic properties of aqualysin I, using sixteen kinds of chromogenic succinyl-tripeptide p-nitroanilides as substrates. And we compared the substrate specificity of aqualysin I with those of proteinase K, subtilisin BPN', and subtilisin Carlsberg. We found that aqualysin I had ...
متن کاملInvolvement of NH2-terminal pro-sequence in the production of active aqualysin I (a thermophilic serine protease) in Escherichia coli.
Aqualysin I is a heat-stable subtilisin-type protease produced by Thermus aquaticus YT-1. The precursor of aqualysin I consists of four domains: an NH2-terminal signal peptide, an NH2-terminal pro-sequence, a protease domain, and a COOH-terminal pro-sequence. In Escherichia coli cells harboring recombinant plasmid carrying the aqualysin I gene, proteolytic activity is obtained on treatment at 6...
متن کاملPresence of thermophilic bacteria in laundry and domestic hot-water heaters.
Thermophilic bacteria resembling Thermus aquaticus were isolated from hot water taken from domestic and commercial hot-water tanks. Cold water from the same locations never yielded thermophilic bacteria, suggesting that the bacteria were growing in the tanks. In contrast to the T. aquaticus isolates from hot springs, the present isolates were rarely pigmented. In general, the hotter sources mor...
متن کاملUnique precursor structure of an extracellular protease, aqualysin I, with NH2- and COOH-terminal pro-sequences and its processing in Escherichia coli.
Aqualysin I is a subtilisin-type serine protease which is secreted into the culture medium by Thermus aquaticus YT-1, an extremely thermophilic Gram-negative bacterium. The nucleotide sequence of the entire gene for aqualysin I was determined, and the deduced amino acid sequence suggests that aqualysin I is produced as a large precursor, consisting of at least three portions, an NH2-terminal pr...
متن کاملEnhancement of the thermostability of subtilisin E by introduction of a disulfide bond engineered on the basis of structural comparison with a thermophilic serine protease.
Sites for Cys substitutions to form a disulfide bond were chosen in subtilisin E from Bacillus subtilis, a cysteine-free bacterial serine protease, based on the structure of aqualysin I of Thermus aquaticus YT-1 (a thermophilic subtilisin-type protease containing two disulfide bonds). Cys residues were introduced at positions 61 (wild-type, Gly) and 98 (Ser) in subtilisin E by site-directed mut...
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