Editing Operon (section)

== Operons versus clustering of prokaryotic genes  ==
All the [[structural gene]]s of an operon are turned ON or OFF together, due to a single promoter and operator upstream to them, but sometimes more control over the gene expression is needed. To achieve this aspect, some bacterial genes are located near together, but there is a specific promoter for each of them; this is called [[Metabolic gene cluster|gene clustering]]. Usually these genes encode proteins which will work together in the same pathway, such as a metabolic pathway. Gene clustering helps a prokaryotic cell to produce metabolic enzymes in a correct order.<ref>{{cite journal | vauthors = Lee JM, Sonnhammer EL | title = Genomic gene clustering analysis of pathways in eukaryotes | journal = Genome Research | volume = 13 | issue = 5 | pages = 875–82 | date = May 2003 | pmid = 12695325 | pmc = 430880 | doi = 10.1101/gr.737703 }}</ref>
In one study, it has been posited that in the [[Asgard (archaea)]], ribosomal protein coding genes occur in clusters that are less conserved in their organization than in other [[Archaea]]; the closer an [[Asgard (archaea)]] is to the [[eukaryote]]s, the more dispersed is the arrangement of the ribosomal protein coding genes.<ref>{{cite journal | vauthors = Tirumalai MR, Sivaraman RV, Kutty LA, Song EL, Fox GE | title = Ribosomal Protein Cluster Organization in Asgard Archaea | journal = Archaea | volume = 2023 |date = September 2003 | pages = 1–16 | doi = 10.1155/2023/5512414 | doi-access = free | pmid = 38314098 | pmc = 10833476 }}</ref>