Class-1 release factor eRF1 promotes GTP binding by class-2 release factor eRF3
2006 (English)In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 88, no 7, 747-757 p.Article in journal (Refereed) Published
In eukaryotes, termination of mRNA translation is triggered by the essential polypeptide chain release factors eRF1, recognizing all three stop codons, and eRF3, a member of the GTPase superfamily with a role that has remained opaque. We have studied the kinetic and thermodynamic parameters of the interactions between eRF3 and GTP, GDP and the non-hydrolysable GTP analogue GDPNP in the presence (K-D(GDP) = 1.3 +/- 0.2 mu M, K-D(GTP) approximate to 200 mu M and K-D(GDPNP) > 160 mu M) as well as absence (K-D(GDP) = 1.9 +/- 0.3 mu M, K-D(GTP) 0.7 +/- 0.2 mu M and K-D(GDPNP) approximate to 200 mu M) of eRF1. From the present data we propose that (i) free eRF3 has a strong preference to bind GDP compared to GTP (ii) eRF3 in complex with eRF1 has much stronger affinity to GTP than free eRF3 (iii) eRF3 in complex with PABP has weak affinity to GTP (iv) eRF3 in complex with eRF1 does not have strong affinity to GDPNP, implying that GDPNP is a poor analogue of GTP for eRF3 binding.
Place, publisher, year, edition, pages
2006. Vol. 88, no 7, 747-757 p.
GTPase, eRF1, eRF3, PABP, GDPNP, GEF, eukaryotes, translation termination, polypeptide release factors
IdentifiersURN: urn:nbn:se:uu:diva-97261DOI: 10.1016/j.biochi.2006.06.001ISI: 000240167100001PubMedID: 16797113OAI: oai:DiVA.org:uu-97261DiVA: diva2:172120