or download this
$seq='GTGGCAAATGCAGAACGTTTTCTGCGTGTTGCCGATATTCTGGAAAGCAATGCCAGGCAAGGGC
+AGGTAGCGACCGTACTTTCCGCCCCCGCGAAAATTACCAACCATCTGGTGGCGATGATTGAAAAAACTA
+TCGGCGGTCAGGATGCTTTGCCGAATATCAGCGATGCCGAACGTATTTTTTCTGACCTGCTCGCAGGAC
+TTGCCAGCGCGCAGCCGGGATTCCCGCTTGCACGGTTGAAAATGGTTGTCGAACAAGAATTCGCTCAGA
+TCAAACATGTTCTGCATGGTATCAGCCTGCTGGGTCAGTGCCCGGATAGCATCAACGCCGCGCTGATTT
+GCCGTGGCGAAAAAATGTCGATCGCGATTATGGCGGGACTCCTGGAGGCGCGTGGACATCGCGTCACGG
+TGATTGATCCGGTAGAAAAATTGCTGGCGGTGGGCCATTACCTTGAATCTACCGTCGATATCGCGGAAT
+CGACTCGCCGTATCGCCGCCAGCCAGATCCCAGCCGATCACATGATCCTGATGGCGGGCTTTACCGCCG
+GTAATGAAAAGGGTGAACTGGTGGTGCTGGGCCGTAATGGTTCCGACTATTCCGCCGCCGTGCTGGCCG
+CCTGTTTACGCGCTGACTGCTGTGAAATCTGGACTGACGTCGATGGCGTGTATACCTGTGACCCGCGTC
+AGGTGCCGGACGCCAGGCTGCTGAAATCGATGTCCTACCAGGAAGCGATGGAACTCTCTTACTTCGGCG
+CCAAAGTCCTTCACCCTCGCACCATTACGCCCATCGCCCAGTTCCAGATCCCCTGTCTGATTAAAAATA
+CCGGTAATCCGCAGGCGCCAGGAACGCTGATCGGCGCGTCCAGCGACGATGATAACCTACCAGTTAAAG
+GGATCTCTAACCTTAACAACATGGCGATGTTTAGCGTCTCCGGCCCGGGAATGAAAGGGATGATTGGGA
+TGGCGGCGCGTGTTTTCGCCGCCATGTCTCGCGCCGGGATCTCGGTGGTGCTCATTACCCAGTCCTCCT
+CTGAGTACAGCATCAGTTTCTGTGTGCCGCAGAGTGACTGCGCGCGTGCCCGCCGTGCGATGCAGGATG
+AGTTCTATCTGGAGCTGAAAGAGGGGCTGCTGGAGCCGCTGGCGGTTACGGAGCGGTTGGCGATTATCT
+CTGTTGTCGGCGACGGTATGCGCACGCTACGCGGCATTTCAGCGAAATTCTTCGCCGCGCTGGCGCGGG
+CCAATATCAATATCGTGGCGATCGCTCAGGGATCTTCTGAGCGTTCCATTTCTGTGGTGGTGAATAACG
+ACGATGCCACCACCGGCGTGCGGGTAACGCACCAGATGCTGTTCAATACCGATCAGGTGATTGAAGTGT
+TTGTCATTGGCGTCGGCGGCGTCGGCGGCGCGCTACTGGAACAGCTTAAACGTCAGCAAACCTGGTTGA
+AGAACAAGCACATCGATCTACGCGTGTGCGGCGTGGCGAACTCAAAGGCGTTGCTAACCAATGTGCATG
+GCCTGAATCTGGACAACTGGCAGGCGGAACTGGCGCAAGCGAACGCGCCGTTCAATCTGGGACGCTTAA
+TTCGCCTGGTGAAAGAATATCATCTACTCAATCCGGTGATTGTTGATTGCACCTCCAGTCAGGCGGTGG
+CCGACCAGTATGCTGACTTCCTGCGTGAAGGATTCCATGTGGTGACGCCAAACAAGAAAGCGAACACCT
+CGTCGATGGACTACTACCATCAGCTACGTTTCGCCGCCGCGCAATCACGGCGCAAATTCTTGTATGACA
+CCAACGTCGGCGCCGGTTTGCCGGTAATCGAAAACCTGCAAAACCTGCTGAATGCGGGTGATGAACTGC
+AAAAATTTTCCGGCATTCTTTCCGGGTCGCTCTCTTTTATTTTCGGTAAACTGGAAGAGGGGATGAGTC
+TCTCACAGGCGACCGCCCTGGCGCGCGAGATGGGCTATACCGAACCCGATCCGCGCGACGATCTTTCCG
+GTATGGATGTGGCGCGGAAACTGTTGATCCTCGCCCGCGAGACGGGCCGCGAGCTGGAGCTTTCCGATA
+TTGTGATTGAACCGGTGTTGCCGGACGAGTTTGACGCCTCCGGCGATGTGACCACCTTTATGGCGCATC
+TGCCGCAGCTTGACGACGCGTTTGCCGCCCGTGTGGCGAAAGCTCGTGATGAAGGTAAGGTATTGCGCT
+ATGTGGGCAATATCGAAGAGGATGGCGTGTGCCGCGTGAAGATTGCCGAAGTTGATGGTAACGATCCGC
+TCTTCAAAGTGAAAAACGGTTAAGAAAACGCGCTGGCGTTCTACAGCCACTATTATCAGCCCTTGCCGT
+TGGTGCTGCGCGGCTACGGCGCAGGCAATGATGTGACGGCGGCGGGCGTGTTTGCCGATCTGTTACGGA
+CCCTCTCATGGAAGTTAGGAGTT';
if($seq=~/.*(ATG.*)/) {$substring_with_correct_start=$1;}