while ($seq{$k} =~ /(([QGYN])
                   ((?!\2)[QGYN]|\2(?!\2))
                   ((?!\3)[QGYN]|\3(?!\3))
                   (?:((?!\4)[QGYN]|\4(?!\4))
                      (?:((?!\5)[QGYN]|\5(?!\5))
                         [QGYN]?)?)?)
                   /xg) {
print "\n$k";
print $1." begins at position ", (pos($seq{$k})-length($s)) , "\n";
}