queuine

Queuine is a modified nucleobase found in transfer RNA (tRNA) molecules, specifically incorporated at the first position of the anticodon loop in tRNA for tyrosine, histidine, asparagine, and aspartic acid. It is a hypermodified derivative of guanine that plays a crucial role in protein synthesis. The queuine modification occurs through a post-transcriptional process where the base is either obtained from dietary sources or synthesized by gut bacteria and subsequently transferred to the host organism. This modification is essential for maintaining the translational fidelity of tRNA, ensuring accurate codon-anticodon recognition during protein synthesis. Research has indicated that queuine may have important biological functions beyond its role in translation, including potential involvement in cellular differentiation and development. Studies have also suggested a possible connection between queuine levels and cancer prevention, as reduced queuine modification has been observed in certain cancer cells. The queuine salvage pathway represents an interesting example of the interplay between diet, microbiota, and cellular function in higher organisms.