>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=99.92 E-value=3.9e-26 Score=196.77 Aligned_cols=248 Identities=29% Similarity=0.322 Sum_probs=188.7 Q ss_pred EEEEEECCCCCHHHHHHHHHH-H---------HHHHCCC----------CCCEECCCEEEEECCC------CEEEEEECC Q ss_conf 389862368504467778864-2---------2210012----------3100012149995178------438888516 Q gi|254780787|r 385 VVTIMGHVDHGKTSLLDAIRK-A---------DVAKGEI----------GGITQHIGAYQVAYQG------KNITFLDTP 438 (884) Q Consensus 385 vv~v~ghvd~GKt~lld~~r~-~---------~~~~~e~----------ggitq~iga~~~~~~~------~~~~~iDtP 438 (884) T Consensus 12 NiGI~AHIDaGKTT~~ERILFy~g~~HkIgE~~g~dG~a~MDwME~E~ERGITItSAAT~~~Wk~~~~~~~~~~N~IDTP 91 (705) T TIGR00484 12 NIGISAHIDAGKTTTTERILFYTGRIHKIGEVHGKDGAATMDWMEQEKERGITITSAATTVEWKGMAKQYDHRINIIDTP 91 (705) T ss_pred CCCEEEEECCCCCCCHHEEEECCCCCCCEEECCCCCCCEECCHHHHCCCCCEEEECHHCCHHHHHHHHCCCCEEEEEECC T ss_conf 54327863388732010100013750100000167885112312300358714210011010210100014037887378 Q ss_pred CHHHHHHHHHHHHHCCCCEEEEEECCCCCCHHHHHHHHHHHHCCCCEEEECCCCCCCCCCCCHHHHHHHCCCC------- Q ss_conf 6157899986664206805999983667402357778989970994156123312443320002210000132------- Q gi|254780787|r 439 GHAAFYEMRARGARVTDIAVLVLAADEEIMPQAIESINHAKAADVSIIVAINKIDKLGADPQKVRMSLLKHDV------- 511 (884) Q Consensus 439 Gh~~f~~~r~rg~~~~d~~ilvv~~~~g~~~qt~e~~~~~~~~~~p~iva~nk~d~~~~~~~~~~~~~~~~~~------- 511 (884) T Consensus 92 GHVDFT~EVERSlRVLDGAv~V~~a~~GV~pQ~~TVwRQa~~Y~VPRi~FVNK~Dk~GAnf~~~~~~~~~rL~~~~~~~q 171 (705) T TIGR00484 92 GHVDFTVEVERSLRVLDGAVAVLDAVGGVQPQSETVWRQANKYEVPRIVFVNKMDKTGANFLRVVNQLKSRLGANAVPIQ 171 (705) T ss_pred CCEEEEEEEEEHHHHHHHHHHHHHHCCCCCCCHHHHHHHHHHCCCCEEEEEECCCCCCCCHHHHHHHHHHHHCCCCEEEE T ss_conf 94125788520122564566533302686641156776543268862899715564578788999999987467734664 Q ss_pred ---CCCC-CCCC-------------------------------------------------------------------- Q ss_conf ---0001-2347-------------------------------------------------------------------- Q gi|254780787|r 512 ---FVES-MGGD-------------------------------------------------------------------- 519 (884) Q Consensus 512 ---~~~~-~~~~-------------------------------------------------------------------- 519 (884) T Consensus 172 lpiGaE~~f~GviDLv~~ka~~~~~~~~g~~~~~~~iP~~~~~~~~~~~~~l~e~~a~~~~~LM~~yl~G~e~~~~~ik~ 251 (705) T TIGR00484 172 LPIGAEDKFIGVIDLVEMKAYFFEEGDKGTKIDEKEIPSDLLEQAKELRENLVEAVAELDEELMEKYLEGEELTIEEIKN 251 (705) T ss_pred ECCCCCCCCCEEEEEEEEEEEEECCCCCCCEEHHHCCCHHHHHHHHHHHHHHHHHHHCCCHHHHHHHCCCCCCCHHHHHH T ss_conf 11256656310455430156775067766400122264789999999999999988420078899850896536899988 Q ss_pred -----------CEEEEEEECCCCCCCCCCCCHHCC------------------CCCCCCCCCCCCCCCCEEEEEEEECCC Q ss_conf -----------403631100247741122100002------------------333342000348666416777886377 Q gi|254780787|r 520 -----------ILDVEISAKNNLNLDKLLDAILLQ------------------AEMLDLKTSINRKAEGIVVEGKLDRGR 570 (884) Q Consensus 520 -----------~~~~~~~~~~~~~~~~~~~~~~~~------------------~~~~~~~~~~~~~~~~~~~~~~~~~~~ 570 (884) T Consensus 252 ~~r~g~l~~~~~pv~~GSafKNKGv~~lLDAV~~yLP~P~dv~~~~~~~~~~~~~e~~~~~sd~~~f~~LAFK~~tdpfv 331 (705) T TIGR00484 252 AIRKGVLNLELIPVLCGSAFKNKGVQLLLDAVVDYLPSPTDVPAIKGIDPDTNEEEIELKASDEEPFVALAFKVATDPFV 331 (705) T ss_pred HHHCCEEEEEEEEEEECCCCHHHHHHHHHHHHHHHCCCCCCHHHHHCCCCCCCCCCEEEEECCCCCCEEEEEEECCCCCC T ss_conf 87513112468888750330002588899999974789743154302355667761367515676512234564058731 Q ss_pred CCCHHHHHHCCHHHCCCCCCCCCC-----CCCCEECCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCEE Q ss_conf 620000000000000000025665-----554200014665322100001222111123475555404 Q gi|254780787|r 571 GPVVTVLVQKGTLSKGNILVVGDQ-----WGKIRALFNDRGQGISKAVPSMPIEVLGLQGMPMAGDKF 633 (884) Q Consensus 571 ~~~~~~~~~~g~~~~~~~~~~~~~-----~~~v~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 633 (884) T Consensus 332 G~LTf~RvY~G~l~~G~~v~Ns~~~k~ervgRl~~MHa~~re~I~~~~aGdI~A~~Glkd~~-TGdTl 398 (705) T TIGR00484 332 GQLTFVRVYSGVLKSGSYVKNSRKSKKERVGRLVKMHANKREEIKEVRAGDIAAAIGLKDTT-TGDTL 398 (705) T ss_pred CEEEEEEEEEEEECCCCEEEECHHHHHHHHHHHHHCCCCCCCCCCCCCCCCEEEEECCEECC-CCCCC T ss_conf 12789999761512797776020000144323331003772100121356368873130025-67632

HHsearch alignment for GI: 254780787 and conserved domain: TIGR00484