TY - JOUR
T1 - Molecular population genetic analysis of the streptokinase gene of Streptococcus pyogenes
T2 - mosaic alleles generated by recombination
AU - Kapur, Vivek
AU - Kanjilal, Sagarika
AU - Hamrick, Marcie R.
AU - Li, Ling‐Ling ‐L
AU - Whittam, Thomas S.
AU - Sawyer, Stanley A.
AU - Musser, James M.
PY - 1995/5
Y1 - 1995/5
N2 - To understand the mechanisms governing molecular evolution of the streptokinase gene skn, a 384 bp DNA fragment encoding two variable regions of the molecule was characterized in 47 isolates of Streptococcus pyogenes. The results reveal that alleles of the streptokinase gene have a mosaic structure, and provide strong evidence for intragenic recombination. Moreover, organisms that are well differentiated in overall chromosomal character have identical skn alleles, which suggests that horizontal gene transfer and recombination have participated in the evolution of this locus. No simple relationship between skn allele and serum opacity factor production or specific disease was identified. The predicted amino acid sequences of highly divergent skn alleles are strikingly similar in hydrophobicity and hydrophobicity profiles, distribution of amphipathic and flexible regions, surface probability plots, and antigenic indices, indicating that despite extensive nucleotide polymorphism in the two skn variable regions, selective pressure has constrained overall structural divergence. These results add to an important emerging theme that intragenic recombination plays a critical role in diversifying genes coding for streptococcal virulence factors.
AB - To understand the mechanisms governing molecular evolution of the streptokinase gene skn, a 384 bp DNA fragment encoding two variable regions of the molecule was characterized in 47 isolates of Streptococcus pyogenes. The results reveal that alleles of the streptokinase gene have a mosaic structure, and provide strong evidence for intragenic recombination. Moreover, organisms that are well differentiated in overall chromosomal character have identical skn alleles, which suggests that horizontal gene transfer and recombination have participated in the evolution of this locus. No simple relationship between skn allele and serum opacity factor production or specific disease was identified. The predicted amino acid sequences of highly divergent skn alleles are strikingly similar in hydrophobicity and hydrophobicity profiles, distribution of amphipathic and flexible regions, surface probability plots, and antigenic indices, indicating that despite extensive nucleotide polymorphism in the two skn variable regions, selective pressure has constrained overall structural divergence. These results add to an important emerging theme that intragenic recombination plays a critical role in diversifying genes coding for streptococcal virulence factors.
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U2 - 10.1111/j.1365-2958.1995.tb02415.x
DO - 10.1111/j.1365-2958.1995.tb02415.x
M3 - Article
C2 - 7565111
AN - SCOPUS:0029054028
SN - 0950-382X
VL - 16
SP - 509
EP - 519
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 3
ER -