Open AccessDefining a minimal cell: essentiality of small ORF s and nc RNA s in a genome‐reduced bacterium
Author(s) -
LluchSenar Maria,
Delgado Javier,
Chen WeiHua,
LlorénsRico Verónica,
O'Reilly Francis J,
Wodke Judith AH,
Unal E Besray,
Yus Eva,
Martínez Sira,
Nichols Robert J,
Ferrar Tony,
Vivancos Ana,
Schmeisky Arne,
Stülke Jörg,
Noort Vera,
Gavin AnneClaude,
Bork Peer,
Serrano Luis
Publication year - 2015
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.15252/msb.20145558
Subject(s) - biology , genome , rna , genetics , bacteria , computational biology , gene
Identifying all essential genomic components is critical for the assembly of minimal artificial life. In the genome‐reduced bacterium Mycoplasma pneumoniae , we found that small ORF s (sm ORF s; < 100 residues), accounting for 10% of all ORF s, are the most frequently essential genomic components (53%), followed by conventional ORF s (49%). Essentiality of sm ORF s may be explained by their function as members of protein and/or DNA / RNA complexes. In larger proteins, essentiality applied to individual domains and not entire proteins, a notion we could confirm by expression of truncated domains. The fraction of essential non‐coding RNA s (nc RNA s) non‐overlapping with essential genes is 5% higher than of non‐transcribed regions (0.9%), pointing to the important functions of the former. We found that the minimal essential genome is comprised of 33% (269,410 bp) of the M. pneumoniae genome. Our data highlight an unexpected hidden layer of sm ORF s with essential functions, as well as non‐coding regions, thus changing the focus when aiming to define the minimal essential genome.