Characterization of a novel prokaryotic GDP dissociation inhibitor domain from the G protein coupled membrane protein FeoB

JOURNAL OF MOLECULAR BIOLOGY

卷:375

Article

Eng, Edward T.¹  Jalilian, Amir R.²  Spasov, Krasimir A.¹  Unger, Vinzenz M.¹ 

[1] Yale Univ, Sch Med, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA

[2] NSTRI, Nucl Med Grp Agr, Med & Ind Res Sch, Karaj, Iran

关键词: bacterial proteins;    GTP-binding protein;    guanine nucleotide dissociation inhibitor;    switch region;    Fe(II)-uptake;   

DOI  :  10.1016/j.jmb.2007.11.027

来源: Elsevier

【 摘 要 】

The FeoB family of membrane embedded G proteins are involved with high affinity Fe(II) uptake in prokaryotes. Here, we report that FeoB harbors a novel GDP dissociation inhibitor-like domain that specifically stabilizes GDP-binding through an interaction with the switch I region of the G protein. We show that the stabilization of GDP binding is conserved between species despite a high degree of sequence variability in their guanine nucleotide dissociation inhibitor (GDI)-like domains, and demonstrate that the presence of the membrane embedded domain increases GDP-binding affinity roughly 150-fold over the level accomplished by action of the GDI-like domain alone. To our knowledge, this is the first example for a prokaryotic GDI, targeting a bacterial G protein-coupled membrane process. Our findings suggest that Fe(II) uptake in bacteria involves a G protein regulatory pathway reminiscent of signaling mechanisms found in higher-order organisms. (c) 2007 Elsevier Ltd. All rights reserved.

【 授权许可】

Free