>TIGR00490 aEF-2 translation elongation factor aEF-2; InterPro: IPR004543 Translation elongation factors are responsible for two main processes during protein synthesis on the ribosome , , . EF1A (or EF-Tu) is responsible for the selection and binding of the cognate aminoacyl-tRNA to the A-site (acceptor site) of the ribosome. EF2 (or EF-G) is responsible for the translocation of the peptidyl-tRNA from the A-site to the P-site (peptidyl-tRNA site) of the ribosome, thereby freeing the A-site for the next aminoacyl-tRNA to bind. Elongation factors are responsible for achieving accuracy of translation and both EF1A and EF2 are remarkably conserved throughout evolution. Elongation factor EF2 (EF-G) is a G-protein. It brings about the translocation of peptidyl-tRNA and mRNA through a ratchet-like mechanism: the binding of GTP-EF2 to the ribosome causes a counter-clockwise rotation in the small ribosomal subunit; the hydrolysis of GTP to GDP by EF2 and the subsequent release of EF2 causes a clockwise rotation of the small subunit back to the starting position , . This twisting action destabilises tRNA-ribosome interactions, freeing the tRNA to translocate along the ribosome upon GTP-hydrolysis by EF2. EF2 binding also affects the entry and exit channel openings for the mRNA, widening it when bound to enable the mRNA to translocate along the ribosome. This entry represents archaeal EF2 proteins (also known as aEF2), which are more similar to eukaryotic EF2 than to bacterial EF2 (or EFG), both in sequence similarity and in sharing with eukaryotes the property of having a diphthamide (modified His) residue at a conserved position. The diphthamide can be ADP-ribosylated by diphtheria toxin in the presence of NAD. More information about these proteins can be found at Protein of the Month: Elongation Factors .; GO: 0003746 translation elongation factor activity, 0005525 GTP binding, 0006414 translational elongation, 0005737 cytoplasm.

Probab=97.75 E-value=9.4e-05 Score=50.61 Aligned_cols=162 Identities=20% Similarity=0.240 Sum_probs=98.3 Q ss_pred CCCCCCCEEEEEECCCCCCHHHHHHHHH-CCC-EE---------EEC----CCCCCEEEE--EEEEEE--ECCEEEEEEE Q ss_conf 4368512189983389986889999986-892-02---------105----888860212--789997--3994899998 Q gi|254780941|r 16 VQDNSRSGCVALVGATNAGKSTLVNRFV-GAK-VS---------IVT----HKVQTTRSI--VRGIVS--EKESQIVFLD 76 (311) Q Consensus 16 ~~~~~ksg~VaivG~pN~GKSTL~N~l~-g~~-vs---------ivS----~k~~TTr~~--i~gi~~--~~~~qiifvD 76 (311) T Consensus 13 m~~~~~irniGi~ahidhGkttlsdnllaGaGmis~elaG~q~~ldfde~e~~rGiti~aanvsmvh~yeG~~ylinlid 92 (724) T TIGR00490 13 MYKPEFIRNIGIVAHIDHGKTTLSDNLLAGAGMISEELAGEQLYLDFDEQEQERGITIDAANVSMVHEYEGNEYLINLID 92 (724) T ss_pred HHHHHHHHHEEEEEEECCCCCHHHHHHHHCCCHHHHHHCCCCEEECCCHHHHHCCCEEEEEEEEEEEEECCCCEEEEEEC T ss_conf 63012221000378631775112234442133234540564100024413523772676411567653147502433314 Q ss_pred CCCCHHHCCCCCCCCCCHHHHHHHHHHHHCCCCHHHHHHHCCHHHHHHHHHHCCCCCEEEEEECCCHHHH---------- Q ss_conf 7984010123575321002345555321001100001000000012234544287202578721101043---------- Q gi|254780941|r 77 TPGIFNAKDSYHKLMIRLSWSTIKHADIVCLVVDSHRELKVNIHDLLKEIAKRSSRLILILNKIDCVKPE---------- 146 (311) Q Consensus 77 TPG~~~~~~~l~~~~~~~~~~~l~~aDiil~VvDa~~~~~~~~~~il~~l~~~~~p~IiVlNKiDlv~~~---------- 146 (311) T Consensus 93 tPGhvdf--------GGdvtramra~dG~~vvv~aveG~mPqtetvlrqal~e~v~Pvlf~nkvdrli~el~l~~~~lq~ 164 (724) T TIGR00490 93 TPGHVDF--------GGDVTRAMRAVDGAIVVVCAVEGVMPQTETVLRQALKENVKPVLFINKVDRLINELKLTPEELQE 164 (724) T ss_pred CCCCCCC--------CCHHHHHHHHHCCEEEEEEECCCCCCCHHHHHHHHHHHCCCEEEEEHHHHHHHHHHCCCHHHHHH T ss_conf 8862105--------62488887764763899950256576157899999873187067723478888862468889999 Q ss_pred HHHHHHHHHH----------------------------HCCCCCCCCCCCCCCCCCHHHHHHHHHHH Q ss_conf 4578888641----------------------------00123343110001387426789999983 Q gi|254780941|r 147 RLLEQAEIAN----------------------------KLVFIEKTFMVSATKGHGCDDVLNYLCST 185 (311) Q Consensus 147 ~l~~~~~~~~----------------------------~~~~~~~i~~ISAk~g~Gid~L~~~L~~~ 185 (311) T Consensus 165 r~~k~i~~~n~li~~m~P~~~~~~W~~~v~~Gs~afGsa~~nWa~~vP~~~~~Gi~f~~~~~~~~e~ 231 (724) T TIGR00490 165 RLIKIIAEVNKLIKKMAPEEFKDKWKVRVEDGSVAFGSAYYNWAISVPIMKKTGITFKDIYKYIKED 231 (724) T ss_pred HHHHHHHHHHHHHHHCCCCCHHCCCEEEECCCCCHHHHHHHHHEEECCCCCCCCCCHHHHHHHHHCC T ss_conf 9999999999999741761000000476515641011222100020443001377599999986301

HHsearch alignment for GI: 254780941 and conserved domain: TIGR00490