DDK Phosphorylates Ctf19
(A) Ctf19 subcomplexes and their members (left) listed next to a schematic of the kinetochore with the Ctf19 complex shown in blue (right).
(B) In vitro phosphorylation of the Ctf19-Mcm21 dimer by DDK. The indicated substrate proteins were incubated with purified DDK and γ-32[P]-ATP. Reaction products were resolved by SDS-PAGE and visualized by autoradiography.
(C) Diagram of Ctf19 showing the fragment resolved crystallographically (dark blue, PDB: 3ZXU) and the unstructured N-terminal region (light blue). Sequence alignment shows the N-terminal fragment. Red boxes indicate candidate phosphorylation motifs. Asterisks mark residues mutated in the ctf19-9A allele.
(D) Ctf19 alleles used in this work. Yellow boxes indicate residues mutated to alanine.
(E) DDK phosphorylates residues in the Ctf19 N-terminal region. Kinase assay performed as in (B). Substrates are indicated below.
See also Figures S1–S3 and Table S1.