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Crystal structure of Rad53 1-466
Structural highlights
FunctionRAD53_YEAST Controls S-phase checkpoint as well as G1 and G2 DNA damage checkpoints. Phosphorylates proteins on serine, threonine, and tyrosine. Prevents entry into anaphase and mitotic exit after DNA damage via regulation of the Polo kinase CDC5. Seems to be involved in the phosphorylation of RPH1.[1] [2] [3] [4] [5] Publication Abstract from PubMedThe vast majority of in vitro structural and functional studies of the activation mechanism of protein kinases use the kinase domain alone. Well-demonstrated effects of regulatory domains or allosteric factors are scarce for serine/threonine kinases. Here we use a site-specifically phosphorylated SCD1-FHA1-kinase three-domain construct of the serine/threonine kinase Rad53 to show the effect of phospho-priming, an in vivo regulatory mechanism, on the autophosphorylation intermediate and specificity. Unphosphorylated Rad53 is a flexible monomer in solution but is captured in an asymmetric enzyme:substrate complex in crystal with the two FHA domains separated from each other. Phospho-priming induces formation of a stable dimer via intermolecular pT-FHA binding in solution. Importantly, autophosphorylation of unprimed and phospho-primed Rad53 produced predominantly inactive pS350-Rad53 and active pT354-Rad53, respectively. The latter mechanism was also demonstrated in vivo. Our results show that, while Rad53 can display active conformations under various conditions, simulation of in vivo regulatory conditions confers functionally relevant autophosphorylation. Phospho-Priming Confers Functionally Relevant Specificities for Rad53 Kinase Autophosphorylation.,Chen ES, Weng JH, Chen YH, Wang SC, Liu XX, Huang WC, Matsui T, Kawano Y, Liao JH, Lim LH, Bessho Y, Huang KF, Wu WJ, Tsai MD Biochemistry. 2017 Sep 26;56(38):5112-5124. doi: 10.1021/acs.biochem.7b00689., Epub 2017 Sep 15. PMID:28858528[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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