Download MendeleyC-terminal motif within Sec7 domain regulates guanine nucleotide exchange activity via tuning protein conformation
Qiu, B., Zhang, K., Wang, S.L., Sun, F.(2014) Biochem Biophys Res Commun 446: 380-386
- PubMed: 24613384
- DOI: https://doi.org/10.1016/j.bbrc.2014.02.125
- Primary Citation of Related Structures:
4OIY - PubMed Abstract:
ADP-ribosylation factors (Arfs) play key roles in controlling membrane traffic and organelle structures. The activation of Arfs from GDP to GTP binding form is triggered by the guanine exchange factors (GEFs). There are six families of Arf-GEFs with a common guanine exchange catalytic domain (Sec7 domain) and various mechanisms of guanine exchange activity regulation. A loop region (loop>J motif) just following the helix J of Sec7 domain was found conserved and important for the catalytic activity regulation of Arf-GEFs. However, the molecular detail of the role the loop>J motif plays has been yet unclear. Here, we studied the catalytic domain of Sec7p, a yeast trans-Golgi network membrane localized Arf-GEFs, and found that the loop>J motif is indispensible for its GEF catalytic activity. Crystallographic, NMR spectrum and mutagenesis studies suggested that the loop>J motif with a key conserved residue Ile1010 modulates the fine conformation of Sec7 domain and thereby regulates its guanine exchange activity.
Organizational Affiliation:
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Graduate School of the Chinese Academy of Sciences, Beijing 100049, China.
