Pyrimidine-specific ribonucleoside hydrolase RihA (IPR022975)

Short name: Pyrim_hydro_RihA

Overlapping homologous superfamilies

Family relationships


The rihA gene encodes a ribonucleoside hydrolase that preferentially utilises cytidine and uridine [PMID: 11027694]. The kcat/KM for uridine is approximately 10 times higher than for cytidine, largely due to a lower KM value for uridine [PMID: 16411753]. There are two other nucleoside hydrolases with differing specificities encoded by the rihB and rihC genes [PMID: 11027694].An rihA null mutant can not use cytidine as a source of pyrimidine and the rihA and rihC genes are subject to catabolite repression [PMID: 11027694].

A crystal structure of RihA bound to the reaction product D-ribose has been solved at 1.8A resolution [PMID: 16411753].

GO terms

Biological Process

GO:0015949 nucleobase-containing small molecule interconversion
GO:0006206 pyrimidine nucleobase metabolic process

Molecular Function

GO:0045437 uridine nucleosidase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.