The conformation of bound GMPPNP suggests a mechanism for gating the active site of the SRP GTPase.

ABSTRACT:

Background

The signal recognition particle (SRP) is a phylogenetically conserved ribonucleoprotein that mediates cotranslational targeting of secreted and membrane proteins to the membrane. Targeting is regulated by GTP binding and hydrolysis events that require direct interaction between structurally homologous "NG" GTPase domains of the SRP signal recognition subunit and its membrane-associated receptor, SR alpha. Structures of both the apo and GDP bound NG domains of the prokaryotic SRP54 homolog, Ffh, and the prokaryotic receptor homolog, FtsY, have been determined. The structural basis for the GTP-dependent interaction between the two proteins, however, remains unknown.

Results

We report here two structures of the NG GTPase of Ffh from Thermus aquaticus bound to the non

SUBMITTER: Padmanabhan S 

PROVIDER: S-EPMC3543820 | biostudies-literature | 2001 Sep

REPOSITORIES: biostudies-literature