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The streptokinase gene of group A streptococci: cloning, expression in Escherichia coli , and sequence analysis
Author(s) -
Huang T.T.,
Malke H.,
Ferretti J. J.
Publication year - 1989
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1989.tb01808.x
Subject(s) - biology , escherichia coli , cloning (programming) , gene , sequence analysis , genetics , sequence (biology) , molecular cloning , streptokinase , microbiology and biotechnology , computational biology , peptide sequence , psychology , psychiatry , myocardial infarction , computer science , programming language
Summary The gene specifying the group A streptokinase ( ska ) gene was cloned from an M type 49 strain of Streptococcus pyogenes and shown to express in Escherichia coli. The nucleotide sequence of the DNA fragment carrying ska was determined and compared to that of the group C streptokinase gene ( skc ). There is 90% sequence identity between the two genes, with highly conserved transcription and translation control regions. The deduced amino acid sequence of the group A streptokinase (SKA) contains the same number of amino acids as that of group C streptokinase, with 85% sequence identity between the two proteins. Among 440 amino acid residues specified by the coding sequence, there are 62 non‐identical residues with 45 conserved and 17 non‐conserved residues. The non‐identical residues are located in two major regions, spanning residues 174 to 244 and 270 to 290, with 40 and 10 amino acid changes, respectively. The sequence differences provide an explanation at the molecular level for the previous findings of immunological and chemical heterogeneity among streptokinases produced by pathogenic streptococci.