RluA

RluA is a bacterial enzyme that functions as a pseudouridine synthase, converting specific uridines to pseudouridines in RNA. It is encoded by the rluA gene and is widespread among bacteria. The enzyme acts primarily on ribosomal RNA of the large subunit (28S-equivalent in bacteria is 23S rRNA) and, in some organisms, on transfer RNA as well. The chemical reaction involves isomerization of uridine to pseudouridine, a process catalyzed by a conserved catalytic aspartate residue in the enzyme’s active site. This modification helps stabilize RNA structure and can influence ribosome folding, translation efficiency, and cellular responses to stress.

RluA belongs to the family of pseudouridine synthases, sharing a common catalytic mechanism and core fold. Substrate recognition is guided by RNA-binding regions that determine site specificity, allowing each enzyme to modify particular uridines within its RNA substrates. The presence of RluA-like enzymes is widespread across bacteria and archaea, where they participate in a coordinated set of ribosomal RNA modifications alongside other pseudouridine synthases.

Genetic and functional studies show that rluA is generally nonessential under standard laboratory conditions, but alterations in its activity can affect growth, stress tolerance, and antibiotic sensitivity in some bacterial species. Research on RluA contributes to a broader understanding of RNA modification biology and its impact on ribosome function and cellular physiology. See also pseudouridine synthase; RumA; RluC; RluD for related enzymes and broader context of RNA modifications.