The PB1 domain and the PC motif-containing region are structurally similar protein binding modules
Yoshinaga, S., Kohjima, M., Ogura, K., Yokochi, M., Takeya, R., Ito, T., Sumimoto, H., Inagaki, F.(2003) EMBO J 22: 4888-4897
- PubMed: 14517229
- DOI: https://doi.org/10.1093/emboj/cdg475
- Primary Citation of Related Structures:
1Q1O - PubMed Abstract:
The PC motif is evolutionarily conserved together with the PB1 domain, a binding partner of the PC motif-containing protein. For interaction with the PB1 domain, the PC motif-containing region (PCCR) comprising the PC motif and its flanking regions is required. Because the PB1 domain and the PCCR are novel binding modules found in a variety of signaling proteins, their structural and functional characterization is crucial. Bem1p and Cdc24p interact through the PB1-PCCR interaction and regulate cell polarization in budding yeast. Here, we determined a tertiary structure of the PCCR of Cdc24p by NMR. The tertiary structure of the PCCR is similar to that of the PB1 domain of Bem1p, which is classified into a ubiquitin fold. The PC motif portion takes a compact betabetaalpha-fold, presented on the ubiquitin scaffold. Mutational studies indicate that the PB1-PCCR interaction is mainly electrostatic. Based on the structural information, we group the PB1 domains and the PCCRs into a novel family, named the PB1 family. Thus, the PB1 family proteins form a specific dimer with each other.
Organizational Affiliation:
Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, N12, W6, Kita-ku, Sapporo 060-0812, Japan.