Crystal structure of the archaeosine synthase QueF-like-Insights into amidino transfer and tRNA recognition by the tunnel fold.

ABSTRACT: The tunneling-fold (T-fold) structural superfamily has emerged as a versatile protein scaffold of diverse catalytic activities. This is especially evident in the pathways to the 7-deazaguanosine modified nucleosides of tRNA queuosine and archaeosine. Four members of the T-fold superfamily have been confirmed in these pathways and here we report the crystal structure of a fifth enzyme; the recently discovered amidinotransferase QueF-Like (QueF-L), responsible for the final step in the biosynthesis of archaeosine in the D-loop of tRNA in a subset of Crenarchaeota. QueF-L catalyzes the conversion of the nitrile group of the 7-cyano-7-deazaguanine (preQ₀ ) base of preQ₀ -modified tRNA to a formamidino group. The structure, determined in the presence of preQ₀ ,

SUBMITTER: Mei X 

PROVIDER: S-EPMC5167649 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature