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The gene encoding a subtilisin-like serine proteinase in the psychrotrophic Vibriosp. PA44 has been successfully cloned, sequenced and expressed in Escherichia coli.The gene is 1593 basepairs and encodes a precursor protein of 530 amino acid residues with a calculated molecular mass of 55.7 kDa. The enzyme is isolated, however, as an active 40.6-kDa proteinase, without a 139amino acid residue N-terminal prosequence. | Eur. J. Biochem. 269 5536-5546 2002 FEBS 2002 doi 10.1046 j.1432-1033.2002.03259.x Characterization of a cloned subtilisin-like serine proteinase from a psychrotrophic Vibrio species I I B B k B B B B B k BB B k BB B b u BB 1 2 B B B B B B B B k BB B k b B BB 1 I B B B BB p I B B k BB B k B B B B B B 2 B BB BB B b B B BB I I p I B BB I B B B k BB B B B k BB b B BB 1 Johanna Arnorsdottir Runa B. Smaradottir Olafur Th. Magnusson Sigridur H. Thorbjarnardottir Gudmundur Eggertsson1 and Magnus M. Kristjansson2 1 Institute of Biology University of Iceland and department of Biochemistry Science Institute University of Iceland Reykjavik Iceland The gene encoding a subtilisin-like serine proteinase in the psychrotrophic Vibrio sp. PA44 has been successfully cloned sequenced and expressed in Escherichia coli. The gene is 1593 basepairs and encodes a precursor protein of 530 amino acid residues with a calculated molecular mass of 55.7 kDa. The enzyme is isolated however as an active 40.6-kDa proteinase without a 139 amino acid residue N-terminal prosequence. Under mild conditions the enzyme undergoes a further autocatalytic cleavage to give a 29.7-kDa proteinase that retains full enzymatic activity. The deduced amino acid sequence of the enzyme has high homology to proteinases of the proteinase K family of subtilisin-like proteinases. With respect to the enzyme characteristics compared in this study the properties of the wild-type and recombinant proteinases are the same. Sequence analysis revealed that especially with respect to the thermophilic homologues aqualysin I from Thermus aquaticus and a proteinase from Thermus strain Rt41A the cold-adapted Vibrio-proteinase has a higher content of polar uncharged amino acids as well as aspartate residues. The thermophilic enzymes had a higher content of arginines and relatively higher number of hydrophobic amino acids and a higher aliphatic index. These factors may contribute to the adaptation of these proteinases to different .
