Portal de Periódicos da CAPES

Structural Basis of Novel Interactions Between the Small-GTPase and GDI-like Domains in Prokaryotic FeoB Iron Transporter

2009; Elsevier BV; Volume: 17; Issue: 10 Linguagem: Inglês

10.1016/j.str.2009.08.007

1878-4186

Motoyuki Hattori, Yaohua Jin, Hiroshi Nishimasu, Yoshiki Tanaka, Masahiro Mochizuki, Toshio Uchiumi, Ryuichiro Ishitani, Koichi Ito, Osamu Nureki,

Enzyme Structure and Function

The FeoB family proteins are widely distributed prokaryotic membrane proteins involved in Fe2+ uptake. FeoB consists of N-terminal cytosolic and C-terminal transmembrane domains. The N-terminal region of the cytosolic domain is homologous to small GTPase (G) proteins and is considered to regulate Fe2+ uptake. The spacer region connecting the G and TM domains reportedly functions as a GDP dissociation inhibitor (GDI)–like domain that stabilizes the GDP-binding state. However, the function of the G and GDI-like domains in iron uptake remains unclear. Here, we report the structural and functional analyses of the FeoB cytosolic domain from Thermotoga maritima. The structure-based mutational analysis indicated that the interaction between the G and GDI-like domains is important for both the GDI and Fe2+ uptake activities. On the basis of these results, we propose a regulatory mechanism of Fe2+ uptake.