Queuosine 5'-phosphate N-glycosylase/hydrolase (also called queuosine salvage protein) is protein which in humans is encoded by the gene QNG1 (previously C9orf64).
Gene QNG1 is located on chromosome 9q21.32. The genes closest to QNG1 on the long arm of chromosome 9 include GKAP1, KIF27, HNRNPK, RMI1, and a MicroRNA MIR7-1.
Tissue distribution
Expression of this gene is highest in the duodenum and small intestine, and it is also expressed in 24 other tissues.
Structure
Queuosine salvage protein is 341 amino acids long with a molecular weight of 39,029 daltons and an isoelectric point of 5.61. The crystal structures of wild-type human QNG1 and QNG1 in complex with queuine have been deposited with the Protein Data Bank under accession numbers 7UGK and 8DL3.
Function
The function and biological process of the queuosine salvage protein is a queuosine-nucleotide N-glycosylase/hydrolase (QNG1) that releases queuine from Q-5'-monophosphate, and this activity is required for the salvage of queuine from exogenous Queuosine by S. pombe and HeLa cells. Some evidence from orthologs indicates it may be involved in tRNA processing and recycling. The most common mRNA contains 4 coding exons, and it has 2 additional alternatively spliced exons. QNG1 has been found in 5 different splice variants.
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