Conformational changes in switch I of EF-G drive its directional cycling on and off the ribosome. Export

@article{citeulike:4937167, abstract = {We have trapped elongation factor G (EF-G) from Escherichia coli in six, functionally defined states, representing intermediates in its unidirectional catalytic cycle, which couples GTP hydrolysis to tRNA-mRNA translocation in the ribosome. By probing EF-G with trypsin in each state, we identified a substantial conformational change involving its conserved switch I (sw1) element, which contacts the GTP substrate. By attaching FeBABE (a hydroxyl radical generating probe) to sw1, we could monitor sw1 movement (by approximately 20 A), relative to the 70S ribosome, during the EF-G cycle. In free EF-G, sw1 is disordered, particularly in GDP-bound and nucleotide-free states. On EF-G*GTP binding to the ribosome, sw1 becomes structured and tucked inside the ribosome, thereby locking GTP onto EF-G. After hydrolysis and translocation, sw1 flips out from the ribosome, greatly accelerating release of GDP and EF-G from the ribosome. Collectively, our results support a central role of sw1 in driving the EF-G cycle during protein synthesis.}, author = {Ticu, Cristina and Nechifor, Roxana and Nguyen, Boray and Desrosiers, Melanie and Wilson, Kevin S.}, citeulike-article-id = {4937167}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/emboj.2009.169}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19536129}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19536129}, doi = {10.1038/emboj.2009.169}, issn = {1460-2075}, journal = {The EMBO journal}, keywords = {ef-g, ntpases, swi-swii}, month = {June}, posted-at = {2009-06-23 22:21:07}, priority = {2}, title = {Conformational changes in switch I of EF-G drive its directional cycling on and off the ribosome.}, url = {http://dx.doi.org/10.1038/emboj.2009.169}, year = {2009} }

TY - JOUR ID - citeulike:4937167 L3 - citeulike-article-id:4937167 N2 - We have trapped elongation factor G (EF-G) from Escherichia coli in six, functionally defined states, representing intermediates in its unidirectional catalytic cycle, which couples GTP hydrolysis to tRNA-mRNA translocation in the ribosome. By probing EF-G with trypsin in each state, we identified a substantial conformational change involving its conserved switch I (sw1) element, which contacts the GTP substrate. By attaching FeBABE (a hydroxyl radical generating probe) to sw1, we could monitor sw1 movement (by approximately 20 A), relative to the 70S ribosome, during the EF-G cycle. In free EF-G, sw1 is disordered, particularly in GDP-bound and nucleotide-free states. On EF-G*GTP binding to the ribosome, sw1 becomes structured and tucked inside the ribosome, thereby locking GTP onto EF-G. After hydrolysis and translocation, sw1 flips out from the ribosome, greatly accelerating release of GDP and EF-G from the ribosome. Collectively, our results support a central role of sw1 in driving the EF-G cycle during protein synthesis. JF - The EMBO journal SN - 1460-2075 TI - Conformational changes in switch I of EF-G drive its directional cycling on and off the ribosome. KW - ef-g KW - ntpases KW - swi-swii AU - Ticu, Cristina AU - Nechifor, Roxana AU - Nguyen, Boray AU - Desrosiers, Melanie AU - Wilson, Kevin PY - 2009/06/18/ UR - http://dx.doi.org/10.1038/emboj.2009.169 ER -