RPSBLAST alignment for GI: 254780484 and conserved domain: cd04171

>gnl|CDD|133371 cd04171, SelB, 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 eukaryotes, they do share a common feature. Unlike in E. coli, these SECIS elements are located in the 3' UTRs. This group contains bacterial SelBs, as well as, one from archaea. Length = 164
 Score = 41.4 bits (98), Expect = 2e-04
 Identities = 21/91 (23%), Positives = 40/91 (43%), Gaps = 5/91 (5%)

Query: 121 LRCVYLLIDCRHGVKQ--IDQ-DVFSFLDKKAVSYQIVLTKIDKLSPTTAQETLEKTKYL 177
           +  V L++    G+     +  ++   L  K     +VLTK D +     +   E+ + L
Sbjct: 75  IDLVLLVVAADEGIMPQTREHLEILELLGIKRGL--VVLTKADLVDEDWLELVEEEIREL 132

Query: 178 IRNYPTAHPEVIPTSSVKRKGIEVLRKAILE 208
           +     A   + P S+V  +GIE L++ + E
Sbjct: 133 LAGTFLADAPIFPVSAVTGEGIEELKEYLDE 163