>TIGR00484 EF-G translation elongation factor G; InterPro: IPR004540 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. EF-G is a large, five-domain GTPase that promotes the directional movement of mRNA and tRNAs on the ribosome in a GTP-dependent manner. Unlike other GTPases, but by analogy to the myosin motor, EF-G performs its function of powering translocation in the GDP-bound form; that is, in a kinetically stable ribosome-EF-G(GDP) complex formed by GTP hydrolysis on the ribosome. The complex undergoes an extensive structural rearrangement, in particular affecting the small ribosomal subunit, which leads to mRNA-tRNA movement. Domain 4, which extends from the 'body' of the EF-G molecule much like a lever arm, appears to be essential for the structural transition to take place. In a hypothetical model, GTP hydrolysis induces a conformational change in the G domain of EF-G, which affects the interactions with neighbouring domains within EF-G. The resulting rearrangement of the domains relative to each other generates conformational strain in the ribosome to which EF-G is fixed. Because of structural features of the tRNA-ribosome complex, this conformational strain results in directional tRNA-mRNA movement. The functional parallels between EF-G and motor proteins suggest that EF-G differs from classical G-proteins in that it functions as a force-generating mechanochemical device rather than a conformational switch . Every completed bacterial genome has at least one copy, but some species have additional EF-G-like proteins. The closest homolog to canonical (e.g. Escherichia coli) EF-G in the spirochetes clusters as if it is derived from mitochondrial forms, while a more distant second copy is also present. Synechocystis sp. (strain PCC 6803) has a few proteins more closely related to EF-G than to any other characterised protein. Two of these resemble E. coli EF-G more closely than does the best match from the spirochetes; it may be that both function as authentic EF-G. 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, 0005622 intracellular.

Probab=98.47 E-value=2.9e-07 Score=66.83 Aligned_cols=246 Identities=20% Similarity=0.231 Sum_probs=142.5 Q ss_pred EEEEECCCCCCHHHHHHHHHCC-----CE-----------------------EEECCCCCCEEEEEEEEEEECCEEEEEE Q ss_conf 8998338998688999998689-----20-----------------------2105888860212789997399489999 Q gi|254780941|r 24 CVALVGATNAGKSTLVNRFVGA-----KV-----------------------SIVTHKVQTTRSIVRGIVSEKESQIVFL 75 (311) Q Consensus 24 ~VaivG~pN~GKSTL~N~l~g~-----~v-----------------------sivS~k~~TTr~~i~gi~~~~~~qiifv 75 (311) T Consensus 12 NiGI~AHIDaGKTT~~ERILFy~g~~HkIgE~~g~dG~a~MDwME~E~ERGITItSA--AT~~~W-k~~~~~~~~~~N~I 88 (705) T TIGR00484 12 NIGISAHIDAGKTTTTERILFYTGRIHKIGEVHGKDGAATMDWMEQEKERGITITSA--ATTVEW-KGMAKQYDHRINII 88 (705) T ss_pred CCCEEEEECCCCCCCHHEEEECCCCCCCEEECCCCCCCEECCHHHHCCCCCEEEECH--HCCHHH-HHHHHCCCCEEEEE T ss_conf 543278633887320101000137501000001678851123123003587142100--110102-10100014037887 Q ss_pred ECCCCHHHCCCCCCCCCCHHHHHHHHHHHHCCCCHHHHHHHCCHHHHHHHHHHCCCCCEEEEEECCCHHHH------HHH Q ss_conf 87984010123575321002345555321001100001000000012234544287202578721101043------457 Q gi|254780941|r 76 DTPGIFNAKDSYHKLMIRLSWSTIKHADIVCLVVDSHRELKVNIHDLLKEIAKRSSRLILILNKIDCVKPE------RLL 149 (311) Q Consensus 76 DTPG~~~~~~~l~~~~~~~~~~~l~~aDiil~VvDa~~~~~~~~~~il~~l~~~~~p~IiVlNKiDlv~~~------~l~ 149 (311) T Consensus 89 DTPGHVD--------FT~EVERSlRVLDGAv~V~~a~~GV~pQ~~TVwRQa~~Y~VPRi~FVNK~Dk~GAnf~~~~~~~~ 160 (705) T TIGR00484 89 DTPGHVD--------FTVEVERSLRVLDGAVAVLDAVGGVQPQSETVWRQANKYEVPRIVFVNKMDKTGANFLRVVNQLK 160 (705) T ss_pred ECCCCEE--------EEEEEEEHHHHHHHHHHHHHHCCCCCCCHHHHHHHHHHCCCCEEEEEECCCCCCCCHHHHHHHHH T ss_conf 3789412--------57885201225645665333026866411567765432688628997155645787889999999 Q ss_pred -----------------------------------------------------HHHHH----------------HHH--- Q ss_conf -----------------------------------------------------88886----------------410--- Q gi|254780941|r 150 -----------------------------------------------------EQAEI----------------ANK--- 157 (311) Q Consensus 150 -----------------------------------------------------~~~~~----------------~~~--- 157 (311) T Consensus 161 ~rL~~~~~~~qlpiGaE~~f~GviDLv~~ka~~~~~~~~g~~~~~~~iP~~~~~~~~~~~~~l~e~~a~~~~~LM~~yl~ 240 (705) T TIGR00484 161 SRLGANAVPIQLPIGAEDKFIGVIDLVEMKAYFFEEGDKGTKIDEKEIPSDLLEQAKELRENLVEAVAELDEELMEKYLE 240 (705) T ss_pred HHHCCCCEEEEECCCCCCCCCEEEEEEEEEEEEECCCCCCCEEHHHCCCHHHHHHHHHHHHHHHHHHHCCCHHHHHHHCC T ss_conf 87467734664112566563104554301567750677664001222647899999999999999884200788998508 Q ss_pred ----------------CC--CCCCCCCCCCCCCCCHHHHHHHHHHHCCCCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHH Q ss_conf ----------------01--233431100013874267899999836622356896433430256789987599999973 Q gi|254780941|r 158 ----------------LV--FIEKTFMVSATKGHGCDDVLNYLCSTLPLAPWVYSADQISDLPMFHFTAEITREKLFLHL 219 (311) Q Consensus 158 ----------------~~--~~~~i~~ISAk~g~Gid~L~~~L~~~lpe~~~~y~~~~~Td~~~~~~i~EiIREki~~~l 219 (311) T Consensus 241 G~e~~~~~ik~~~r~g~l~~~~~pv~~GSafKNKGv~~lLDAV~~yLP~-P~dv~~~~~~~~~~~-------~~e~~~~~ 312 (705) T TIGR00484 241 GEELTIEEIKNAIRKGVLNLELIPVLCGSAFKNKGVQLLLDAVVDYLPS-PTDVPAIKGIDPDTN-------EEEIELKA 312 (705) T ss_pred CCCCCHHHHHHHHHCCEEEEEEEEEEECCCCHHHHHHHHHHHHHHHCCC-CCCHHHHHCCCCCCC-------CCCEEEEE T ss_conf 9653689998887513112468888750330002588899999974789-743154302355667-------76136751 Q ss_pred HCCCCCC---EEEEEEEEECCCCCCEEEEEEE------EEECCCCCEEEECCCCHHHHHHHHHHHHHHHHHHCCCCEEEE Q ss_conf 0045642---0478853310667723589999------982798415487466588999999999999998489813789 Q gi|254780941|r 220 HKEIPYS---SCVVTEKWEEKKDGSILIRQVI------YVERPSQKKIMLGKNGQNIKTISLEAKKEIAEILEQPVHLIL 290 (311) Q Consensus 220 ~~EiPY~---~~v~v~~~~~~~~~~~~I~~~I------~v~k~sqk~IiiGk~G~~ik~I~~~ar~~le~~~~~~V~L~l 290 (311) T Consensus 313 sd~~~f~~LAFK~~tdpfvG-~LTf~RvY~G~l~~G~~v~Ns~~~k~erv----gRl~~MHa~~re~I~~~~aGdI~A~~ 387 (705) T TIGR00484 313 SDEEPFVALAFKVATDPFVG-QLTFVRVYSGVLKSGSYVKNSRKSKKERV----GRLVKMHANKREEIKEVRAGDIAAAI 387 (705) T ss_pred CCCCCCEEEEEEECCCCCCC-EEEEEEEEEEEECCCCEEEECHHHHHHHH----HHHHHCCCCCCCCCCCCCCCCEEEEE T ss_conf 56765122345640587311-27899997615127977760200001443----23331003772100121356368873 Q ss_pred EEE Q ss_conf 988 Q gi|254780941|r 291 FVK 293 (311) Q Consensus 291 ~Vk 293 (311) T Consensus 388 Glk 390 (705) T TIGR00484 388 GLK 390 (705) T ss_pred CCE T ss_conf 130

HHsearch alignment for GI: 254780941 and conserved domain: TIGR00484