5niy

Publication Abstract from PubMed

The Escherichia coli signal recognition particle (SRP) receptor, FtsY, plays a fundamental role in co-translational targeting of membrane proteins via the SRP pathway. Efficient targeting relies on membrane interaction of FtsY and heterodimerization with the SRP protein Ffh, which is driven by detachment of alpha helix (alphaN1) in FtsY. Here we show that apart from the heterodimer, FtsY forms a nucleotide-dependent homodimer on the membrane, and upon alphaN1 removal also in solution. Homodimerization triggers reciprocal stimulation of GTP hydrolysis and occurs in vivo. Biochemical characterization together with integrative modeling suggests that the homodimer employs the same interface as the heterodimer. Structure determination of FtsY NG+1 with GMPPNP shows that a dimerization-induced conformational switch of the gamma-phosphate is conserved in Escherichia coli, filling an important gap in SRP GTPase activation. Our findings add to the current understanding of SRP GTPases and may challenge previous studies that did not consider homodimerization of FtsY.

The Escherichia coli SRP Receptor Forms a Homodimer at the Membrane.,Kempf G, Stjepanovic G, Sloan J, Hendricks A, Lapouge K, Sinning I Structure. 2018 Aug 8. pii: S0969-2126(18)30254-5. doi:, 10.1016/j.str.2018.07.008. PMID:30146170^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.