Open reading frames:

In several cases these days, the protein encoded through a particular gene is deduced through cloning and then sequencing the corresponding DNA.  An DNA sequence  is after that scanned  using a computer  program  to recognized  runs of codons  which  begin  with  ATG  and  end  with  TAG,  TAA  or TGA.  These runs of codons are known open reading frames (ORFs) and identify potential coding regions.  Since  genes  hold out important  cellular  functions,  the sequence  of coding   DNA   (and   of   important   regulatory   sequences)   is   more   strongly conserved  in evolution  which  that  of noncoding  DNA.  In specific,  mutations which lead  to the creation  of termination  codons  within  the coding  region,  and while   premature   termination  in  during   translation,   are  choosen   against.   This means in which the coding regions of genes frequently contain comparatively  long ORFs through  in noncoding  DNA,  triplets  corresponding  to termination  codons  are not selected  against  and ORFs are comparatively  short.  Therefore, when analyzing the ORFs displayed for a particular cloned DNA, it is commonly true that a long ORF is likely to be coding DNA while short ORFs may not be. Yet, one must be aware that some exons can be short and so some short ORFs may also be coding   DNA. The Computer   analysis   may be able to detect these through screening for the conserved sequences at exon/intron boundaries and the splice branchpoint sequence. At last, through referring to the genetic code and computer analysis can predict the protein sequence encoded through each ORF. This is deduced of protein series.