ORF, Open reading frame

Figure 7.5 Model of ferritin (and erythroid a-aminolaevulinate synthase) translation/ribosome binding regulation by IRP. In (a), with IRP not bound to the IRE (1) binding of the 43S preinitiation complex (consisting of the small ribosomal 40S subunit, GTP and Met-tRNAMet) to the mRNA is assisted by initiation factors associated with this complex, as well as additional eukaryotic initiation factors (elFs) that interact with the mRNA to facilitate 43S association. Subsequently (2), the 43S preinitiation complex moves along the 5 -UTR towards the AUG initiator codon, (3) GTP is hydrolysed, initiation factors are released and assembly of the 80S ribosome occurs. Protein synthesis from the open reading frame (ORF) can now proceed. In (b) With IRP bound to the IRE, access of the 43S preinitiation complex to the mRNA is sterically blocked. From Gray and Hentze, 1994, by permission of Oxford University Press.

A well accepted meaning for the term functional genomics has been the research activities leading to the identification of the function of open reading frames (ORF) in complete genome sequences. The focus is on the particular ORFs that have no similarity to other sequences of known function and that, if removed from the... 

Open manometers, 20 646—647 Open-mold process, for unsaturated polyesters, 20 116-117 Open-mold processing, 19 558 Open-pit zinc mining, 26 557 Open reading frames (ORFs), 26 480, 481 with yeasts, 26 491—492 Open system... 

An open reading frame (ORF) is a sequence of nucleotides in the RNA or DNA that has the potential to encode protein. The start triplet is ATG. It is followed by a string of triplets that code for amino acids. The stop triplet is TAA, TAG, or TGA (see Exhibit A2.2). 

In a DNA sequencing project, an open reading frame (ORF) has been identified. The nucleotide sequence includes a coding region for an SH2 domain in the protein product. This potential protein is most likely to... 

A stretch of DNA that is transcribed as a single continuous RNA strand is called a transcription unit. A unit of transcription may contain one or more sequences encoding different polypeptide chains (translational open reading frames, ORF) or cistrons. The transcription unit is sometimes termed the primary transcript, pre-messenger RNA or heterogeneous nuclear RNA (hnRNA). The primary transcript is further processed to produce mRNA in a form that is relatively stable and readily participates in translation. In order to understand the primary need for processing of this RNA, the biochemical definition of a gene must be discussed. 

Genome sizes, complete proteomes, and the number of open reading frames (ORFs) were all retrieved from http //www.ncbi.nlm.nih.gov. Taken, with permission, from Islas et al., 2004. 

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