The guanine nucleotide exchange factor Rlf interacts with SH3 domain-containing proteins via a binding site with a preselected conformation.Popovic, M., Jakobi, A.J., Rensen-de Leeuw, M., Rehmann, H.
(2013) J Struct Biol 183: 312-319
- PubMed: 23891840
- DOI: https://doi.org/10.1016/j.jsb.2013.07.009
- Primary Citation of Related Structures:
- PubMed Abstract:
Rlf is a guanine nucleotide exchange factor for the small G-proteins RalA and RalB and couples Ras- to Ral-signalling. Here the crystal structure of the catalytic module of Rlf consisting of a REM- and a CDC25-homology domain is determined. The structure is distinguished by an extended three stranded β-sheet called the flagpole. The flagpole is a conserved element in the RalGDS family of guanine nucleotide exchange factors and stabilises the orientation of the REM-domain relative to the CDC25-homology domain. A proline-rich sequence in the flagpole is unique to Rlf and several proteins that interact with this sequence by SH3 domains are identified. Conformational pre-selection results in a gain of affinity and contributes to the establishment of SH3 domain selectivity.
Department of Molecular Cancer Research, Centre of Biomedical Genetics and Cancer Genomics Centre, University Medical Center Utrecht, Utrecht, The Netherlands.