RT Journal
A1 Johnson, Zackary I.
A1 Chisholm, Sallie W.
T1 Properties of overlapping genes are conserved across microbial genomes
JF Genome Research 
JO Genome Research 
YR 2004 
FD November 01 
VO 14 
IS 11 
SP 2268 
OP 2272 
DO 10.1101/gr.2433104 
UL http://genome.cshlp.org/content/14/11/2268.abstract 
AB There are numerous examples from the genomes of viruses, mitochondria, and chromosomes that adjacent genes can overlap, sharing at least one nucleotide. Overlaps have been hypothesized to be involved in genome size minimization and as a regulatory mechanism of gene expression. Here we show that overlapping genes are a consistent feature (approximately one-third of all genes) across all microbial genomes sequenced to date, have homologs in more microbes than do non-overlapping genes, and are therefore likely more conserved. In addition, the size, phase (reading frame offset), and distribution, among other characteristics, of overlapping genes are most consistent with the hypothesis that overlaps function in the regulation of gene expression. The upstream sequences and conservation of overlapping orthologs of two model organisms from the genus Prochlorococcus that have significantly different GC-content, and therefore different nucleotide sequences for orthologs, are also consistent with small overlapping sequence regions and programmed shifts in reading frame as a common mechanism in the regulation of microbial gene expression.