>cd01889 SelB_euk SelB subfamily. SelB is an elongation factor needed for the co-translational incorporation of selenocysteine. Selenocysteine is coded by a UGA stop codon in combination with a specific downstream mRNA hairpin. In bacteria, the C-terminal part of SelB recognizes this hairpin, while the N-terminal part binds GTP and tRNA in analogy with elongation factor Tu (EF-Tu). It specifically recognizes the selenocysteine charged tRNAsec, which has a UCA anticodon, in an EF-Tu like manner. This allows insertion of selenocysteine at in-frame UGA stop codons. In E. coli SelB binds GTP, selenocysteyl-tRNAsec and a stem-loop structure immediately downstream of the UGA codon (the SECIS sequence). The absence of active SelB prevents the participation of selenocysteyl-tRNAsec in translation. Archaeal and animal mechanisms of selenocysteine incorporation are more complex. Although the SECIS elements have different secondary structures and conserved elements between archaea and euk

Probab=99.85 E-value=3.7e-21 Score=156.73 Aligned_cols=157 Identities=24% Similarity=0.272 Sum_probs=113.2 Q ss_pred EEEEECCCCCCHHHHHHHHHCCCEEEECCC------CCCEEEEE--------------EEEEEECCEEEEEEECCCCHHH Q ss_conf 899833899868899999868920210588------88602127--------------8999739948999987984010 Q gi|254780941|r 24 CVALVGATNAGKSTLVNRFVGAKVSIVTHK------VQTTRSIV--------------RGIVSEKESQIVFLDTPGIFNA 83 (311) Q Consensus 24 ~VaivG~pN~GKSTL~N~l~g~~vsivS~k------~~TTr~~i--------------~gi~~~~~~qiifvDTPG~~~~ 83 (311) T Consensus 2 NV~iiGHVDhGKTTL~~~L~~~~~~~~~D~~~eE~eRGITi~~g~~~~~~~~~~~~~~~~~~~~~~~~i~~IDtPG---- 77 (192) T cd01889 2 NVGVLGHVDSGKTSLAKALSEIASTAAFDKNPQSQERGITLDLGFSSFYVDKPKHLRELINPGEENLQITLVDCPG---- 77 (192) T ss_pred EEEEEEECCCCHHHHHHHHHHHCCCHHHHCCHHHHHCCCCEEEEEEEEEECCCCCCCCCCCCCCCCEEEEEEECCC---- T ss_conf 8999976178999999999833350122135889977971671001378514422112323467745899987798---- Q ss_pred CCCCCCCCCCHHHHHHHHHHHHCCCCHHHHHHHCCHHHHHHHHHHCCCCCEEEEEECCCHHHHHHHHHH----HHHHH-- Q ss_conf 123575321002345555321001100001000000012234544287202578721101043457888----86410-- Q gi|254780941|r 84 KDSYHKLMIRLSWSTIKHADIVCLVVDSHRELKVNIHDLLKEIAKRSSRLILILNKIDCVKPERLLEQA----EIANK-- 157 (311) Q Consensus 84 ~~~l~~~~~~~~~~~l~~aDiil~VvDa~~~~~~~~~~il~~l~~~~~p~IiVlNKiDlv~~~~l~~~~----~~~~~-- 157 (311) T Consensus 78 ----H~df~~~~~~g~~~~D~ailvVda~~G~~~QT~eh~~~~~~~~~~~iv~iNK~D~v~~~~~~~~~~~i~~~l~~~l 153 (192) T cd01889 78 ----HASLIRTIIGGAQIIDLMLLVVDATKGIQTQTAECLVIGEILCKKLIVVLNKIDLIPEEERERKIEKMKKKLQKTL 153 (192) T ss_pred ----CHHHHHHHHHHHHHCCCCEEEEECCCCCCHHHHHHHHHHHHCCCCEEEEEECCCCCCHHHHHHHHHHHHHHHHHHH T ss_conf ----3889988888874326527999878888789999999999858997999974127881577999999999999998 Q ss_pred -C--CCCCCCCCCCCCCCCCHHHHHHHHHHHCCC Q ss_conf -0--123343110001387426789999983662 Q gi|254780941|r 158 -L--VFIEKTFMVSATKGHGCDDVLNYLCSTLPL 188 (311) Q Consensus 158 -~--~~~~~i~~ISAk~g~Gid~L~~~L~~~lpe 188 (311) T Consensus 154 ~~~~~~~~~iipiSA~~G~gi~eL~~~i~~lip~ 187 (192) T cd01889 154 EKTRFKNSPIIPVSAKPGGGEAELGKDLNNLIVL 187 (192) T ss_pred HHCCCCCCEEEEEECCCCCCHHHHHHHHHHHCCC T ss_conf 6538999849995789884989999888761899

HHsearch alignment for GI: 254780941 and conserved domain: cd01889