Structure and Function of a sno‐like RNA in Haloferax volcanii

Abstract

Small nucleolar RNA (snoRNA) is known to guide modification of RNA in eukaryotes and archaea. In this study, the structure and function of a conserved halophile sno‐like RNA (sRNA) from the moderately halophilic archaeon, Haloferax volcanii (Hvo.), has been characterized using genetic and biochemical methods. The sRNA is predicted to guide 2′‐O‐ ribose methylation of cytidine‐34 (C34) in elongator methionine tRNA (met tRNA). Northern analysis, RT‐PCR walking and RT‐PCR of cyclized sRNA show that the sRNA is likely to be cotranscibed with an adjoining gene and processed from a larger transcript. A mutant strain of Hvo. (δsRNA) has been constructed in which the sRNA gene has been deleted. The mutant exhibits normal growth, indicating that this gene is not essential. An RNase H cleavage assay has been used to characterize the methylation of met tRNA isolated from wild‐type and δsRNA strains. Preliminary results suggest that the mutant may be lacking in methylation at C34. This work furthers our understanding of the mechanisms of tRNA maturation in the archaea. This work was supported by a NSF grant to CJD and JH (MCB‐0620005).