ORF1ab
Open reading frame
Summary
ORF1ab refers collectively to two open reading frames (ORFs), ORF1a and ORF1b, that are conserved in the genomes of nidoviruses, a group of viruses that includes coronaviruses. The genes express large polyproteins that undergo proteolysis to form several nonstructural proteins with various functions in the viral life cycle, including proteases and the components of the replicase-transcriptase complex (RTC). Together the two ORFs are sometimes referred to as the replicase gene. They are related by a programmed ribosomal frameshift that allows the ribosome to continue translating past the stop codon at the end of ORF1a, in a -1 reading frame. The resulting polyproteins are known as pp1a and pp1ab.
Originally created by Opabinia regalis
11/15/2021, 7:04:31 AM
Modified
5/24/2026, 12:10:04 AM
Recent revisions
([[c:GR|GR]]) [[c:COM:FR|File renamed]]: [[File:1-s2.0-S0006291X20320593-gr3 lrg.jpg]] → [[File:Nidovirus genome phylogeny.jpg]] [[c:COM:FR#FR2|Criterion 2]] (meaningless or ambiguous name)
change page parameter to article-number
Removed parameters. | [[:en:WP:UCB|Use this bot]]. [[:en:WP:DBUG|Report bugs]]. | #UCB_CommandLine
Added doi-broken-date. | [[:en:WP:UCB|Use this bot]]. [[:en:WP:DBUG|Report bugs]]. | #UCB_CommandLine
Alter: journal. Add: pmc, doi-access. | [[:en:WP:UCB|Use this bot]]. [[:en:WP:DBUG|Report bugs]]. | #UCB_CommandLine
Added a link to the coronavirus nsp12 page
[[Wikipedia:OABOT|Open access bot]]: doi added to citation with #oabot.
Fixing [[Wikipedia:Disambiguation pages with links|links to disambiguation pages]], replaced: [[PCR]] → [[Polymerase chain reaction|PCR]]
/* Evolution */ ORF1ab is a target of PCR tests (sourced)
consistent citation formatting
Adding [[Wikipedia:Short description|short description]]: "Open reading frame" ([[Wikipedia:Shortdesc helper|Shortdesc helper]])
Alter: journal. Add: s2cid, bibcode, doi-access, pmc, pmid. | [[WP:UCB|Use this bot]]. [[WP:DBUG|Report bugs]]. | Suggested by Abductive | #UCB_toolbar
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/* References */ added [[Template:Viral proteins]] NavBox
ce
add replicase, use protein infoboxes for full length polyproteins
/* Evolution */ add specific proteins
evolution section
/* Processing */ full version of image + caption
/* Components */ ce, typo
