This gene encodes a subunit of tRNA-guanine transglycosylase. tRNA-guanine transglycosylase is a heterodimeric enzyme complex that plays a critical role in tRNA modification by synthesizing the 7-deazaguanosine queuosine, which is found in tRNAs that code for asparagine, aspartic acid, histidine, and tyrosine. The encoded protein may play a role in the queuosine 5'-monophosphate salvage pathway. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene.