Réponses antivirales chez le moustique Aedes

@article{12020,

title = {Adaptation of the Romanomermis culicivorax CCA-Adding Enzyme to Miniaturized Armless tRNA Substrates },

author = {O Hennig and S Philipp and S Bonin and K Rollet and T Kolberg and T Jühling and H Betat and C Sauter and M Mörl

},

url = {https://www.mdpi.com/1422-0067/21/23/9047},

doi = {10.3390/ijms21239047 },

year  = {2020},

date = {2020-11-28},

journal = {International Journal of Molecular Sciences},

volume = {21},

number = {23},

pages = {E9047},

abstract = {The mitochondrial genome of the nematode Romanomermis culicivorax encodes for miniaturized hairpin-like tRNA molecules that lack D- as well as T-arms, strongly deviating from the consensus cloverleaf. The single tRNA nucleotidyltransferase of this organism is fully active on armless tRNAs, while the human counterpart is not able to add a complete CCA-end. Transplanting single regions of the Romanomermis enzyme into the human counterpart, we identified a beta-turn element of the catalytic core that-when inserted into the human enzyme-confers full CCA-adding activity on armless tRNAs. This region, originally identified to position the 3'-end of the tRNA primer in the catalytic core, dramatically increases the enzyme's substrate affinity. While conventional tRNA substrates bind to the enzyme by interactions with the T-arm, this is not possible in the case of armless tRNAs, and the strong contribution of the beta-turn compensates for an otherwise too weak interaction required for the addition of a complete CCA-terminus. This compensation demonstrates the remarkable evolutionary plasticity of the catalytic core elements of this enzyme to adapt to unconventional tRNA substrates. },

keywords = {CCA-adding enzyme, co-evolution, evolutionary plasticity, FRUGIER, minimalized armless tRNAs, tRNA nucleotidyltransferase, Unité ARN},

pubstate = {published},

tppubtype = {article}

}