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The PB1 domain and the PC motif‐containing region are structurally similar protein binding modules
Author(s) -
Yoshinaga Sosuke,
Kohjima Motoyuki,
Ogura Kenji,
Yokochi Masashi,
Takeya Ryu,
Ito Takashi,
Sumimoto Hideki,
Inagaki Fuyuhiko
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg475
Subject(s) - library science , biology , national laboratory , graduate students , engineering , engineering physics , computer science , medical education , medicine
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 ββα‐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.