Systematizing the genomic order and relatedness in the open reading frames (ORFs) of the coronaviruses

Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved..

The coronaviruses (CoVs), including SARS-CoV-2, the agent of the ongoing deadly CoVID-19 pandemic (Coronavirus disease-2019), represent a highly complex and diverse class of RNA viruses with large genomes, complex gene repertoire, and intricate transcriptional and translational mechanisms. The 3'-terminal one-third of the genome encodes four structural proteins, namely spike, envelope, membrane, and nucleocapsid, interspersed with genes for accessory proteins that are largely nonstructural and called 'open reading frame' (ORF) proteins with alphanumerical designations, but not in a consistent or sequential order. Here, I report a comparative study of these ORF proteins, mainly encoded in two gene clusters, i.e. between the Spike and the Envelope genes, and between the Membrane and the Nucleocapsid genes. For brevity and focus, a greater emphasis was placed on the first cluster, collectively designated as the 'orf3 region' for ease of referral. Overall, an apparently diverse set of ORFs, such as ORF3a, ORF3b, ORF3c, ORF3d, ORF4 and ORF5, but not necessarily numbered in that order on all CoV genomes, were analyzed along with other ORFs. Unexpectedly, the gene order or naming of the ORFs were never fully conserved even within the members of one Genus. These studies also unraveled hitherto unrecognized orf genes in alternative translational frames, encoding potentially novel polypeptides as well as some that are highly similar to known ORFs. Finally, several options of an inclusive and systematic numbering are proposed not only for the orf3 region but also for the other orf genes in the viral genome in an effort to regularize the apparently confusing names and orders. Regardless of the ultimate acceptability of one system over the others, this treatise is hoped to initiate an informed discourse in this area.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:92

Enthalten in:

Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases - 92(2021) vom: 15. Aug., Seite 104858

Sprache:

Englisch

Beteiligte Personen:

Barik, Sailen [VerfasserIn]

Links:

Volltext

Themen:

Accessory genes
Coronaviridae
Coronavirus
Journal Article
Open reading frame
Phylogeny
RNA genome
Viral Proteins

Anmerkungen:

Date Completed 09.07.2021

Date Revised 21.12.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.meegid.2021.104858

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM324036396