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2021
Wijn R. De, Rollet K., G.M.Ernst F., Wellner K., Betat H., Mörl M., Sauter M.
In: Computational and Structural Biotechnology Journal, vol. 19, pp. 5845-5855, 2021, ISBN: ISBN/2001-0370.
Abstract | Links | BibTeX | Tags: CCA-adding enzyme, Cold adaptation, Psychrophilic protein, Psychrophilic RNA polymerase, SAUTER, SAXS, tRNA, Unité ARN, X-ray crystallography
@article{nokey,
title = {CCA-addition in the cold: Structural characterization of the psychrophilic CCA-adding enzyme from the permafrost bacterium Planococcus halocryophilus},
author = {R. De Wijn and K. Rollet and F. G.M.Ernst and K. Wellner and H. Betat and M. Mörl and M. Sauter},
url = {https://www.sciencedirect.com/science/article/pii/S2001037021004402?via%3Dihub},
doi = {10.1016/j.csbj.2021.10.018},
isbn = {ISBN/2001-0370},
year = {2021},
date = {2021-01-01},
journal = {Computational and Structural Biotechnology Journal},
volume = {19},
pages = {5845-5855},
abstract = {CCA-adding enzymes are highly specific RNA polymerases that add and maintain the sequence C-C-A at tRNA 3ﾑ-ends. Recently, we could reveal that cold adaptation of such a polymerase is not only achieved at the expense of enzyme stability, but also at the cost of polymerization fidelity. Enzymes from psychrophilic organisms usually show an increased structural flexibility to enable catalysis at low temperatures. Here, polymerases face a dilemma, as there is a discrepancy between the need for a tightly controlled flexibility during polymerization and an increased flexibility as strategy for cold adaptation. Based on structural and biochemical analyses, we contribute to clarify the cold adaptation strategy of the psychrophilic CCA-adding enzyme from Planococcus halocryophilus, a gram-positive bacterium thriving in the arctic permafrost at low temperatures down to −15 °C. A comparison with the closely related enzyme from the thermophilic bacterium Geobacillus stearothermophilus reveals several features of cold adaptation - a significantly reduced amount of alpha-helical elements in the C-terminal tRNA-binding region and a structural adaptation in one of the highly conserved catalytic core motifs located in the N-terminal catalytic core of the enzyme},
keywords = {CCA-adding enzyme, Cold adaptation, Psychrophilic protein, Psychrophilic RNA polymerase, SAUTER, SAXS, tRNA, Unité ARN, X-ray crystallography},
pubstate = {published},
tppubtype = {article}
}
CCA-adding enzymes are highly specific RNA polymerases that add and maintain the sequence C-C-A at tRNA 3ﾑ-ends. Recently, we could reveal that cold adaptation of such a polymerase is not only achieved at the expense of enzyme stability, but also at the cost of polymerization fidelity. Enzymes from psychrophilic organisms usually show an increased structural flexibility to enable catalysis at low temperatures. Here, polymerases face a dilemma, as there is a discrepancy between the need for a tightly controlled flexibility during polymerization and an increased flexibility as strategy for cold adaptation. Based on structural and biochemical analyses, we contribute to clarify the cold adaptation strategy of the psychrophilic CCA-adding enzyme from Planococcus halocryophilus, a gram-positive bacterium thriving in the arctic permafrost at low temperatures down to −15 °C. A comparison with the closely related enzyme from the thermophilic bacterium Geobacillus stearothermophilus reveals several features of cold adaptation - a significantly reduced amount of alpha-helical elements in the C-terminal tRNA-binding region and a structural adaptation in one of the highly conserved catalytic core motifs located in the N-terminal catalytic core of the enzyme
2020
Hennig O, Philipp S, Bonin S, Rollet K, Kolberg T, Jühling T, Betat H, Sauter C, Mörl M
Adaptation of the Romanomermis culicivorax CCA-Adding Enzyme to Miniaturized Armless tRNA Substrates Journal Article
In: International Journal of Molecular Sciences, vol. 21, no. 23, pp. E9047, 2020.
Abstract | Links | BibTeX | Tags: CCA-adding enzyme, co-evolution, evolutionary plasticity, minimalized armless tRNAs, SAUTER, tRNA nucleotidyltransferase, Unité ARN
@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, minimalized armless tRNAs, SAUTER, tRNA nucleotidyltransferase, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
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.
