α his h1029

α-PCNA (P8825) and α-HIS (H1029) were purchased from Sigma; α-RIF1 (A300-568A) was purchased from Bethyl; α-PP1α (sc-271762) and α-PP2α (sc-56950) were purchased from Santa Cruz Biotechnology.
Affinity purified α-Cdc45, α-Psf2 (30 (link)), α-Mcm4 antibodies (31 (link)), α-Mcm7 (32 (link)), α-RecQ4 and α-TopBP1 antibodies were previously described (33 (link)). Similarly, α-GINS (34 (link)), α-Treslin and α-MTBP were described in (18 (link)).
Xenopus full-length DONSON protein was purified as described above and antibodies raised against such prepared antigens in sheep or rabbit. The resulting antibody sera was purified in-house against the purified antigen. The specificity of each new antibody is presented in Supplementary Figure S1.

α-PCNA (P8825), α-His (H1029), and α-ubiquitin (P4D1) were purchased from Sigma-Aldrich and α-phospho-histone H3 (ser10) (D2C8) was purchased from Cell Signalling Technology. α-TRAIP (NBP1-87125) and α-RNF213 (NBP1-88466) were purchased from Novus Biologicals. α-SUMO2 and α-SUMO1 were produced in the laboratory by culturing the hybridoma cell lines SUMO2 (8A2), and SUMO1 (21C7), purchased from Developmental Studies Hybridoma Bank (hybridoma cell culture was performed following the manufacturer’s instructions and adding 20 mM L-glutamine to the media). Affinity-purified α-Cdc45, α-Psf2, and α-Sld5 (Gambus et al, 2011 (link)); α-Mcm3 (Khoudoli et al, 2008 (link)); α-SMC2 (Gillespie et al, 2007 (link)); and α-LRR1 (S962D) (Sonneville et al, 2017 (link)) were previously described. α-Mcm7 was raised in sheep against recombinant X. laevis Mcm7, purified from E. coli, and affinity-purified in the laboratory.

α-PCNA (P8825) and α-HIS (H1029) were purchased from Sigma; α-Cul2 (EPR3104) was purchased from Abcam; α-p97 (65278) was purchased from Progen Biotechnik, anti-P-Chk1 (S345) from Cell Signaling, γ-H2AX (4418-APC-020, Trevigen).
Affinity purified α-Cdc45, α-Psf2 (40 (link)), α-Mcm3 (41 (link)), α-LRR1 (S962D) and α-Cul2 (SA206) (4 (link)), and α-Mcm7 (6 ) were previously described. Xenopus Ufd1 antibody was a kind gift from Prof Stemmann’s lab (13 (link)).
Xenopus full-length p97, Ubxn7, Faf1, and GINS proteins were purified as described previously (6 , 13 (link)) and antibodies raised against such prepared antigens in sheep (p97, GINS, Ubxn7) or rabbit (Faf1). The resulting antibody sera were purified in-house against the purified antigen. The specificity of each new antibody is presented in Fig S7.