Functional differentiation and cooperative interaction between two eukaryote-like archaeal Orc1/Cdc6 proteins on the replication origin.
The DNA replication apparatus of archaea represents a core version of that in eukaryotes. Archaeal Orc1/Cdc6s can be an integral component in the replication machineries cooperatively regulating DNA replication. We investigated the DNA-binding activities of two eukaryote-like Orc1/Cdc6 proteins (SsoCdc6-1 and -2) and interactions between them on the different structural duplex DNA substrates derived from oriC1 of Sulfolobus solfataricus. The results showed that two Orc1/Cdc6 proteins stimulated mutual DNA-binding activities at lower concentrations and formed bigger SsoCdc6-1/SsoCdc6-2/DNA complex at higher concentrations. Furthermore, SsoCdc6-2 stimulated the DNA-binding activity of SsoMCM and demonstrated a high affinity to the 5-forked DNA. In contrast, SsoCdc6-1 inhibited the binding of SsoMCM and demonstrated better affinity to the sequence-specific blunt DNA substrate. Finally, we found that the two proteins physically interacted with each other and with SsoMCM. Thus, the two Orc1/Cdc6 proteins were functionally different, but they may keep the coordinated interaction on the replication origin.
Jiang
Pei-Xia
PX
Center for Proteomics Research, National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Feng
Ying
Y
He
Zheng-Guo
ZG
D018797:Cell Cycle Proteins / Q000378:metabolism*; D004261:DNA Replication / Q000502:physiology*; D051738:Origin Recognition Complex / Q000378:metabolism*; D018741:Replication Origin / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D016944:Sulfolobus / Q000378:metabolism*
C066503:CDC6 protein, S cerevisiae; D018797:Cell Cycle Proteins; D051738:Origin Recognition Complex; D029701:Saccharomyces cerevisiae Proteins