1.14.11.42	physiological function	knock-down of enzyme gene by RNAi results in loss of hydroxywybutosine. Expression of the gene in yeast leads to formation of hydroxywybutosine. Enzyme Tyw5p employs wybutosine residue 72 in tRNAPhe as a substrate by recognizing the N4-methyl group to hydroxylate the beta-carbon of the propyl group, followed by methylation and methoxycarbonylation of the side chain catalyzed by enzyme Tyw4 for completion	725408