The solution structure of an N-terminally truncated version of the yeast CDC24p PB1 domain shows a different beta-sheet topology
D. Leitner, M. Wahl, D. Labudde, G. Krause, A. Diehl, P. Schmieder, J.R. Pires, M. Fossi, U. Wiedemann, M. Leidert, H. Oschkinat
FEBS Lett.(2005) 579, 3534 - 3538
Phox and Bem1 (PB1) domains mediate protein-protein interactions via the formation of homo- or hetero-dimers. The C-terminal PB1 domain of yeast cell division cycle 24 (CDC24p), a guanine-nucleotide exchange factor involved in cell polarity establishment, is known to interact with the PB1 domain occurring in bud emergence MSB1 interacting 1 (BEM1p) during the regulation of the yeast budding process via its OPR/PC/AID (OPCA) motif. Here, we present the structure of an N-terminally truncated version of the Sc CDC24p PB1 domain. It shows a different topology of the beta-sheet than the long form. However, the C-terminal part of the structure shows the conserved PB1 domain features including the OPCA motif with a slight rearrangement of helix alpha1. Residues which are important for the heterodimerization with BEM1p are structurally preserved.