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bioRxiv · 10.1101/2021.02.01.429250

Molecular mechanism of N-terminal acetylation by the ternary NatC complex

Deng, S.·Gottlieb, L.·Pan, B.·Supplee, J.·Wei, X.·Petersson, J.·Marmorstein, R.
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Abstract

Protein N-terminal acetylation is predominantly a ribosome-associated modification, with NatA-E serving as the major enzymes. NatC is the most unusual of these enzymes, containing one Naa30 catalytic subunit and two auxiliary subunits, Naa35 and Naa38; and substrate specificity profile that overlaps with NatE. Here, we report the Cryo-EM structure of S. pombe NatC with a NatE/C-type bisubstrate analogue and inositol hexaphosphate (IP6), and associated biochemistry studies. We find that the presence of three subunits is a prerequisite for normal NatC acetylation activity in yeast and that IP6 binds tightly to NatC to stabilize the complex. We also describe the molecular basis for IP6-mediated NatC complex stabilization and the overlapping yet distinct substrate profiles of NatC and NatE.

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Deng, S., Gottlieb, L., Pan, B., Supplee, J., Wei, X., Petersson, J., Marmorstein, R.. 2021-02-02. Molecular mechanism of N-terminal acetylation by the ternary NatC complex. https://doi.org/10.1101/2021.02.01.429250

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