Figure 1.

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.