Use of uninitialized value $1... Because, $1 is in fact undefined in your example.

my $procount2 = 1;

foreach my $readingframe2(@protein){
    my $protein;
    print "string is $_\n";
    
    if(/MHGR/){
        print "$1\n","motif is $_\n";  ##### <----- 
        if(length($_)>=1){
           print "length of motif is length($_)\n";
           print OUT1 "Protein $procount2\n$_\n";
           $procount2++;
        }
    }
}

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In reply to Re: Regular expression problems by pvaldes
in thread Regular expression problems by rattytatty

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